Krivitsky's old friend, Ignaz Reiss, was beginning to have great doubts about the truth of the Show Trials. His wife, Elsa Poretsky, had visited Moscow in early 1937. She noted that: "The Soviet citizen does not rejoice in the splendor, he does not marvel at the blood trials, he hunches down deeper, hoping only perhaps to escape ruin. Before every Party member the dread of the purge. Over every Party member and non-Party member the lash of Stalin. Lack of initiative it's called, then lack of vigilance - counter-revolution, sabotage, Trotskyism. Terrified to death, the Soviet man hastens to sign resolutions. He swallows everything, says yea to everything. He has become a clod. He knows no sympathy, no solidarity. He knows only fear."

Ignaz Reiss met with Krivitsky and suggested that they should both defect in protest as a united demonstration against the purge of leading Bolsheviks. Krivitsky rejected the idea. He suggested that the Spanish Civil War would probably revive the old revolutionary spirit, empower the Comintern and ultimately drive Stalin from power. Krivitsky also made the point that that there was no one to whom they could turn. Going over to Western intelligence services would betray their ideals, while approaching Leon Trotsky and his group would only confirm Soviet propaganda, and besides, the Trotskists would probably not trust them.

Krivitsky was recalled to Moscow. He later commented that he took the opportunity to "find out at firsthand what was going on in the Soviet Union". Krivitsky wrote that Joseph Stalin had lost the support of most of the Soviet Union: "Not only the immense mass of the peasants, but the majority of the army, including its best generals, a majority of the commissars, 90 percent of the directors of factories, 90 percent of the Party machine, were in more or less extreme degree opposed to Stalin's dictatorship."

Walter Krivitsky met up with Ignaz Reiss in Rotterdam on 29th May, 1937. He told Reiss that Moscow was a "madhouse" and that Nikolai Yezhov was "insane". Krivitsky agreed with Reiss that the Soviet Union had "devolved into a Fascist state" but refused to defect. Krivitsky later explained: "The Soviet Union is still the sole hope of the workers of the world. Stalin may be wrong. Stalins will come and go, but the Soviet Union will remain. It is our duty to stick to our post." Reiss disagreed with Krivitsky and said if that was his view he would go it alone. Elsa Poretsky also began to doubt the loyalty of Krivitsky. She began to wonder why he had been allowed to leave Moscow. She told her husband: "No one leaves the Soviet Union unless the NKVD can use him."

In July 1937 Ignaz Reiss was warned that if he did not go back to the Soviet Union at once he would be "treated as a traitor and punished accordingly". Reiss responded by sending a letter to the Soviet Embassy in Paris explaining his decision to break with the Soviet Union because he no longer supported the views of Stalin's counter-revolution and wanted to return to the freedom and teachings of Lenin. "Up to this moment I marched alongside you. Now I will not take another step. Our paths diverge! He who now keeps quiet becomes Stalin's accomplice, betrays the working class, betrays socialism. I have been fighting for socialism since my twentieth year. Now on the threshold of my fortieth I do not want to live off the favours of a Yezhov. I have sixteen years of illegal work behind me. That is not little, but I have enough strength left to begin everything all over again to save socialism. ... No, I cannot stand it any longer. I take my freedom of action. I return to Lenin, to his doctrine, to his acts." These letters were addressed to Joseph Stalin and Abram Slutsky.

Mikhail Shpiegelglass told Krivitsky that Ignaz Reiss had gone over to the Trotskyists and described him meeting Henricus Sneevliet in Amsterdam. Krivitsky assumed from this information that Stalin had a spy within Sneevliet's group. Krivitsky correctly guessed that this was Mark Zborowski. Krivitsky and another NKVD agent, Theodore Maly, tried to contact Reiss. Recently released NKVD files show that Shpiegelglass ordered Maly to take an iron and beat Reiss to death in his hotel room. Maly refused to carry out this order and criticised Shpiegelglass in his report to Moscow.

According to Edward P. Gazur, the author of Alexander Orlov: The FBI's KGB General (2001): "On learning that Reiss had disobeyed the order to return and intended to defect, an enraged Stalin ordered that an example be made of his case so as to warn other KGB officers against taking steps in the same direction. Stalin reasoned that any betrayal by KGB officers would not only expose the entire operation, but would succeed in placing the most dangerous secrets of the KGB's spy networks in the hands of the enemy's intelligence services. Stalin ordered Yezhov to dispatch a Mobile Group to find and assassinate Reiss and his family in a manner that would be sure to send an unmistakable message to any KGB officer considering Reiss's route."

Reiss was found hiding in a village near Lausanne, Switzerland. It was claimed by Alexander Orlov that a trusted Reiss family friend, Gertrude Schildback, went for supper outside of town. They left the restaurant and set off on foot. A car pulled up bearing two NKVD agents, Francois Rossi and Etienne Martignat. One was driving, the other - holding a machine-gun. Reiss was shot seven times in the head and five times in the body. The assassins fled, not bothering to check out of the hotel in Lausanne. They abandoned the car in Berne. The police found a box of chocolates, laced with strychnine, in the hotel room. It is believed these were intended for Elsa and her son Roman.

Abram Slutsky now grew very suspicious of Krivitsky and insisted that he turned over his spy-ring to Mikhail Shpiegelglass. This included his second in command, Hans Brusse. Soon afterwards, Brusse made contact with Krivitsky and told him that Shpiegelglass had ordered him to kill Elsa Poretsky and her son. Krivitsky advised him to accept the mission, but to sabotage the operation. Krivitsky also suggested that Brusse should gradually withdraw from working for the NKVD. According to Krivitsky's account in I Was Stalin's Agent (1939), Brusse agreed to this strategy.

After the assassination of Ignaz Reiss, Krivitsky discovered that Theodore Maly, who had refused to kill him, was recalled and executed. He now decided to defect to Canada. Once settled abroad he would collaborate with Paul Wohl on the literary projects they had so often discussed. In addition to writing about economic and historical subjects, he would be free to comment on developments in the Soviet Union. Wohl agreed to the proposal. He told Krivitsky that he was an exceptional man with rare intelligence and rare experience. He assured him that there was no doubt that together they could succeed.

Wohl agreed to help Walter Krivitsky defect. To help him disappear he rented a villa for him in Hyères, a small town in France on the Mediterranean Sea. On 6th October, 1937, Wohl arranged for a car to collect Krivitsky, Antonina Porfirieva and their son and to take them to Dijon. From there they took a train to their new hideout on the Côte d'Azur. As soon as he discovered that Krivitsky had fled, Mikhail Shpiegelglass told Nikolai Yezhov what had happened. After he received the report, Yezhov sent back the command to assassinate Krivitsky and his family.

Later that month Krivitsky wrote to Elsa Poretsky and told her what he had done and to express concerns that the NKVD had a spy close to her friend, Henricus Sneevliet. "Dear Elsa, I have broken with the Firm and am here with my family. After a while I will find the way to you, but right now I beg you not to tell anyone, not even your closest friends, who this letter is from... Listen well, Elsa, your life and that of your child are in danger. You must be very careful. Tell Sneevliet that in his immediate vicinity informers are at work, apparently also in Paris among the people with whom he has to deal. He should be very attentive to your and your child's welfare. We both are completely with you in your grief and embrace you." He gave the letter to Gerard Rosenthal, who took it to Sneevliet who passed it onto Poretsky.

On 7th November, 1937, Krivitsky returned to Paris where Paul Wohl arranged for him to meet Lev Sedov, the son of Leon Trotsky, and the leader of the Left Opposition in France an editor of the Bulletin of the Opposition. Sedov put him in touch with Fedor Dan, who had a good relationship with Leon Blum, the leader of the French Socialist Party and a member of the Popular Front government. Although it took several weeks, Krivitsky received French papers and if needed, a police guard.

Krivitsky also arranged a meeting with Hans Brusse who he hoped to persuade him to defect. Brusse refused declaring that he had come to the meeting "in the name of the organization". He then pulled out a copy of Krivitsky's letter to Elsa. Krivitsky was deeply shocked, but denied having written the letter. He suspected that he knew he was lying. Brusse pleaded with Krivitsky to return to his work as a Soviet spy.

Walter Krivitsky and Paul Wohl decided to try to move to the United States. Wohl who spoke English, would go ahead first, get settled and make arrangements for Krivitsky to follow. Wohl managed to become a foreign correspondent for a Czech newspaper. He obtained a U.S. visitor's visa valid for sixty days and traveled as a German refugee.

On 5th November 1938, Krivitsky, Antonina Porfirieva and their son, boarded the French liner Normandie, and set off for America. However, when they arrived at New York they were refused permission to enter the country. For the next few days they were kept on Ellis Island. With the help of David Shub, he was eventually allowed to stay at the apartment that Wohl had found for him at 600 West 140th Street. The two men immediately got to work writing articles on the Soviet Union. Shub also put the men in touch with journalist, Isaac Don Levine, who had good contacts with the American media.

Levine realised that this "slight, short and unimposing, though noteworthy for the striking contrast between his deep blue eyes, keen with intelligence" was a source of extraordinary material. He told Krivitsky that he could get him a lucrative deal for a series of articles. The first of these articles appeared in the Saturday Evening Post in April 1939. J. Edgar Hoover was very angry when he read the article. He was extremely annoyed that the American public had discovered in the article that Joseph Stalin was "sending NKVD agents into the United States as if the the FBI did not exist".

On 7th January, 1941, Paul Wohl contacted Suzanne La Follette and told her to inform Walter Krivitsky that he had seen Hans Brusse in New York City. He added the comment: "I want him (Krivitsky) to remain alive to envy the fate of Medusa for having been allowed to die at the sight of her own image." Wohl later told the FBI that he had seen the tall Dutchman was wearing a European overcoat, grayish-green with raglan sleeves, and carrying a dark brown leather briefcase. When he heard the news, Krivitsky became convinced that Brusse was in the country to organize his assassination. Krivitsky told his lawyer, Louis Waldman: "Mr. Waldman, it is now finished. I am a dead man. Hans never misses."

On Thursday 6th February, 1941, Krivitsky visited Eitel Wolf Dobert on his 90-acre farm in Barboursville, about 15 miles north of Charlottesville. The Doberts moved into a two-room log cabin and decided to raise chickens. Margarita later recalled: "My God, it was hard! We nearly starved. When we made $50 a month it was a great month." Krivitsky told Dobert he planned to buy a farm in Virginia.

Soon after arriving Krivitsky purchased a .38 caliber Colt automatic pistol and cartridges at the Charlottesville Hardware store. On his return to the farm he and Dobert began target practice. By 8th February he had run out of ammunition. Margarita Dobert later commented: "On Saturday he asked me to drive to town and buy 150 cartridges for the gun."

On Sunday 9th February, Walter Krivitsky checked into the Bellevue Hotel in Washington at 5:49 p.m. He paid $2.50 in advance for the room and signed his name in the register as Walter Poref. The desk clerk, Joseph Donnelly, described him afterwards as nervous and trembling. At 6:30, he called down for a bottle of Vichy sparkling water. The bellboy considered him a typical foreigner - "quiet and solemn".

The young maid, Thelma Jackson, knocked on Krivitsky's room at 9.30. When she did not receive an answer she assumed the room was free for cleaning and inserted her passkey. She opened the door and discovered a man lying on the bed the wrong way round, with his head toward the foot. She noticed he had "blood all over his head". The police were called and Sergeant Dewey Guest diagnosed the case as an obvious suicide. Coroner MacDonald issued a certificate of suicide that afternoon.

Krivitsky left behind three suicide notes, each one in a different language known to him (English, German and Russian). Police handwriting expert, Ira Gullickson, was shown the notes found with the body and declared that they were without any question written by the man who signed the hotel register. Gullickson argued that the notes were written on different times, because they showed an increase in nervous tension.

The first letter, in English, was addressed to Louis Waldman: "Dear Mr. Waldman: My wife and my boy will need your help. Please do for them what you can. I went to Virginia because that there I can get a gun. If my friends should have trouble please Mr. Waldman help them, they are good people and they didn't know why I bought the gun. Many thanks."

The second suicide note, in German, was addressed to Suzanne La Follette: "Dear Suzanne: I believe you that you are good, and I am dying with the hope that you will help Tonia and my poor boy. You were a good friend." This letter raised several issues. It is true that in the early days of their relationship he did write in German because his English was poor. However, in recent letters, he had used English.

The third letter was to his wife, Antonina Porfirieva: "Dear Tonia and dear Alek. Very difficult and very much want to live but I can't live any longer. I love you my only ones. It's difficult for me to write but think about me and you will understand that I have to go. Don't tell Alek yet where his father has gone. I believe that in time you will explain since it will be good for him. Forgive difficult to write. Take care of him and be a good mother - as always be strong and never get angry at him. He is after all such a such a good and such a poor boy. Good people will help you but not enemies of the Soviet people. Great are my sins I think. I see you Tonia and Alek and embrace you."

Gary Kern, the author of A Death in Washington: Walter G. Krivitsky and the Stalin Terror (2004) claims that two sentences in this letter cause certain problems: "Good people will help you but not enemies of the Soviet people. Great are my sins I think." He goes on to argue: "These two statements have the look of a political recantation and, as such, suggest either a mental breakdown or something dictated by the NKVD."

On hearing of Krivitsky's death, his lawyer, Louis Waldman, called a press conference and announced that he had been murdered by the NKVD and named the killer as Hans Brusse. (1) An NKVD agent (Hans Brusse) who had twice before tried to trap Krivitsky had appeared in New York City, where Krivitsky lived. (2) Krivitsky planned to buy a farm in Virginia, thus he intended to live. He had changed his name, applied for citizenship, bought a car. (3) The NKVD was expert in forgery and had samples of Krivitsky's hand in every language.

At the White House, Adolf Berle, President Roosevelt's advisor on national security wrote in his diary: "General Krivitsky was murdered in Washington today. This is an OGPU job. It means that the murder squad which operated so handily in Paris and in Berlin is now operating in New York and Washington." Joseph Brown Matthews, who was an investigator for the House Committee on Un-American Activities, commented: "It's murder. I have no doubt of it." New York Times reported that Krivitsky had told them: "If they ever try to prove that I took my own life, don't believe them."

One of the most surprising aspects of the case was that rooms on both sides of Krivitsky had been occupied. So had the rooms across the hall. In the past, guests had often complained about noises in the room next to them because of the thinness of the walls. However, no one heard gunfire in the quiet early morning hours when the suicide had taken place. The gun found in Krivitsky's room did not have a silencer.

The Washington Post argued: "All in all, it would seem that the Washington police and coroner disposed of the case in rather summary fashion... The whole thing looks like a pretty careless piece of work." Frank Waldrop of The Washington Times-Herald ridiculed the police investigation: "Anybody'd rather be a second-guessing citizen than Chief of Police Ernest W. Brown, with such a staff of lunkheads to do the field work in homicide matters." However The Daily Worker disagreed: "The capitalist press is desperately trying to make a frame-up murder case out of what is clearly established in the suicide of General Walter Krivitsky."

Alexander Kerensky believed Hans Brusse had murdered Krivitsky: "Hans Brusse is the man. The most vicious murderer in all the Soviet. We know him. We know his methods. His favourite tactic is to drive a man to suicide by threatening to capture and torture his family. It has been done many times in many countries. I believe Krivitsky got a concrete warning recently that they would kill him or kidnap his family. That is their favourite plan of operation. Krivitsky had a burning mission to expose Stalin for what he is. And in my opinion he was not the type to commit suicide."

Whittaker Chambers definitely believed that he had been killed by the NKVD: "He had left a letter in which he gave his wife and children the unlikely advice that the Soviet Government and people were their best friends. Previously he had warned them that, if he were found dead, never under any circumstances to believe that he had committed suicide." Krivitsky once told Chambers: "Any fool can commit a murder, but it takes an artist to commit a good natural death." Martin Dies, Isaac Don Levine and Suzanne La Follette all believed Krivitsky was murdered.

However, Eitel Wolf Dobert, told reporters that Krivitsky seemed very worried and probably had committed suicide. He also thought that Krivitsky had written his suicide notes the last night that he stayed on his farm. Mark Zborowski, who was later exposed as a NKVD agent who had been involved in the death of Lev Sedov, also believed Krivitsky committed suicide. He told David Dallin: "He was a neurasthenic and a paranoiac, eternally in fear of assassination. He felt that he was a traitor. As a Communist, he did not have the right to do what he was doig. He had days of high spirits and days of dejection."

Paul Wohl also disagreed he had been murdered. He said: "When we lived together, he often talked of suicide." Wohl also dismissed the idea that Hans Brusse killed Krivitsky. He claimed that although he was a Soviet agent he was not the type "to be assigned to assassinations, but rather a technician". Gary Kern, the author of A Death in Washington: Walter G. Krivitsky and the Stalin Terror (2004) has pointed out: "If Hans were so innocuous, one has to wonder, then why had Wohl sent his letter of warning to Krivitsky in the first place... And if he were not an assassin, but a technician, then what was he doing in America on a political assignment? And how did Wohl, a private citizen, know about any of these things?"

Jan Valtin, a former NKVD agent also took the view that Krivitsky was murdered. He said the NKVD liquidated people on foreign soil for three main reasons: "(1) To silence someone with secrets who might talk, has talked or will go on talking. (2) To eliminate someone who could be an asset to foreign intelligence services. (3) To wreak vengeance on someone who tried to break away from the Soviet Secret Service and thus to demonstrate an ability to prosecute defectors anywhere in the world, with the consequent chilling effect on potential defectors still in the service."

Another former agent, Hede Gumperz, also explained how they would have arranged his death. "The only possible lever they could have tried to use against him was his family - threatening to kill his wife and son, and promising to spare their lives only if he took his. But Krivitsky would have known with absolute certainty that, even if the threats were serious, the promises were not. After all, he himself, as a senior officer in the same service, had seen so many promises of clemency which had been made in the name of Stalin cynically broken the moment their aim was achieved."

Krivitsky's wife, Antonina Porfirieva, believed it was a forced suicide. The main clue came from his letter: "Very difficult and very much want to live but I can't live any longer. I love you my only ones. It's difficult for me to write but think about me and you will understand that I have to go." Antonina, who had worked for the NKVD and knew about the methods they used: "I am convinced that my husband was forced to write the notes he left behind... Walter had utter contempt for suicide and would have never killed himself willingly. They forced him to write those notes and then they forced him to kill himself. He made a deal with them to save me and our boy."

Louis Waldman campaigned for the FBI to treat the case as murder. "The issue is much deeper than the discovery of whether the general's death was the result of murder or suicide... When one considers that General Krivitsky was a witness, giving valuable information as to foreign espionage in our own country to a legislative committee, to the State Department, and to the FBI itself, then in my opinion, there is the clear duty of the FBI to track down those malevolent forces which were responsible for his death."

Waldman told the FBI that he had evidence that Hans Brusse was the killer. When the FBI reopen the case he went to the press with his evidence. Recently released documents show that in March 1941 a certain Lee Y. Chertok, a Russian living in the United States, claimed to have information on the killers of Krivitsky. J. Edgar Hoover sent a memo telling the FBI not to follow up this evidence: "The Bureau is not interested in determining whether Krivitsky was murdered or whether he committed suicide."

Brusse went missing after the death of Walter Krivitsky. In 1948 Hans sent his mother a picture postcard without a post mark - it must have been carried by hand - stating that he was living in a "far-off land". He seems to be unaware that his mother had died in 1941.

Jan Jongert says he saw Brusse in Rotterdam in 1956. Another source told MI6 that Brusse was living in an East European country in the late 1950s. It was assumed that he was still working for the Soviet intelligence service.