Hitler's threat to invade Czechoslovakia in September 1938

Adolf Hitler's threat to invade Czechoslovakia in September 1938 turned a territorial dispute into an immediate test of whether diplomatic pressure could avert war. By setting a deadline for invasion and announcing imminent mobilisation, Hitler compressed the time available to Britain and France to respond. The threat also brought two forms of resistance into collision: Neville Chamberlain's effort to maintain a peaceful settlement, and a clandestine German opposition's plan to stop Hitler if he ordered mobilisation.

Background and Ultimatum

The immediate diplomatic proposal was an orderly transfer of the Sudeten territory to Germany, subject to a plebiscite, which the Czechoslovak Government had agreed to accept. Hitler would not wait even a week: Chamberlain told his ministers that Hitler had announced an invasion for Saturday. After meeting Hitler in Berlin, Sir Horace Wilson warned him that Britain would be obliged to support France if France fulfilled its treaty obligations to Czechoslovakia. According to the British ambassador, Hitler replied that he was prepared for every eventuality and that, if France and Britain struck, he would regard it with indifference; he predicted that the countries would be at war by the following Monday.

The threat was also framed through claims about violence against Sudeten Germans. At a later meeting, Wilson reported that Hitler had described Czechoslovakia as a threat to European peace and asserted that a quarter of a million refugees had fled the Sudetenland into Germany in the preceding days. Hitler demanded that the disputed territory begin to be evacuated by Saturday, warning that otherwise he would march in. He kept looking at his watch, as if measuring the remaining time before the temporary pause in mobilisation expired. Wilson judged that Hitler was not bluffing: in his account, the choice was to settle the crisis that day or face war.

British Response and the Cost of Signalling

At a meeting with the Chiefs of Staff, Chamberlain set out the breakdown of negotiations and the threatened invasion. Hugh Legat recorded the discussion in the Cabinet Room, where Lord Gort sat centrally as the senior officer and Chamberlain reviewed the latest report from Berlin. The Prime Minister said that he would continue seeking a peaceful solution, though he could see little more to be done, and that Britain must prepare for the worst.

The military response itself carried risks. When the Chiefs of Staff said partial mobilisation would have to begin that day to be operational by 1 October, Chamberlain recognised that Britain would be mobilising before Germany. The officers argued that partial mobilisation could show Hitler that Britain was not bluffing and might make him reconsider. Chamberlain countered that the signal could instead push Hitler into war: from his two meetings with Hitler, he believed that Hitler could not tolerate losing face. One officer warned that sincere peace efforts might be mistaken for weakness, recalling the German misjudgment of Britain's resolve in 1914. The discussion left the central dilemma unresolved: a demonstration of readiness might strengthen deterrence, or make retreat more difficult.

The German Opposition's Contingency

The same deadline gave urgency to a secret plan within the German opposition. General Ludwig Beck disclosed that he had resigned as Chief of the General Staff nearly six weeks earlier in protest at the plan to go to war with Czechoslovakia. He had kept his resignation private after promising Hitler not to make it public, but remained in contact with former colleagues in the high command. Beck believed that if Hitler ordered mobilisation, the Army might disobey and move against the regime.

Beck also explained why the Army could not openly initiate a coup: its members had sworn an oath of loyalty to Hitler. In his account, the Army could enter the Chancellery to restore order after a disturbance, but the first move against Hitler would have to come from someone else. Colonel Hans Oster had worked out the practical requirements with Captain Friedrich Heinz. With surprise and an assurance that the Army would prevent an SS rescue attempt, they estimated that about fifty men could arrest Hitler. Heinz said that the force already existed and was prepared to act the next day.

The conspirators postponed arguments about the form of government that might follow the Third Reich and agreed to make stopping the mobilisation order their immediate priority. They would take Hitler alive if he surrendered; if he appeared likely to escape, Oster said they might have to shoot him. Hugh Legat was the first to agree, the others followed, and Beck assented only reluctantly. Their decision was explicit: they would strike the next day. The threat of invasion had thus become the trigger for a plan whose success depended not only on preparation, but on the Army's willingness to act.

The Column and the Postponement

In Berlin, the danger acquired a visible form when an armoured column moved south along Wilhelmstrasse. It included artillery half-tracks, tanks on transporters, heavy guns towed by trucks, and horse teams; Hugh Legat's former friend Paul von Hartmann judged it, from its length, to be a full motorised division. Erich Kordt told Hartmann that Hitler had ordered the movement half an hour after a meeting and that it was no accident the column was passing the British Embassy. Kordt identified the troops as those of General Witzleben's Berlin garrison, heading for the Czech frontier. The column made the threat seem to have crossed from announcement into action.

The timetable changed when a message from Sir Nevile Henderson reached Legat in London at seven minutes past two. Henderson reported that Benito Mussolini had sent a message through the Italian ambassador: Italy would stand by Germany in a conflict, but Mussolini asked Hitler to postpone mobilisation for twenty-four hours so the situation could be reconsidered. Hitler had agreed. The intervention bought time, but did not cancel mobilisation or settle the dispute. In a later discussion, Oster said that everything had depended on Walther von Brauchitsch, who was still deciding what to do when Hitler issued the postponement order. A delay that opened diplomatic space also removed the immediate moment on which the conspirators' plan had depended.

Consequences and Significance

The German opposition did not treat the postponement as a resolution. With the Army's position uncertain and the prospect of a Munich agreement growing, Hartmann argued that the remaining chance was to prevent the agreement from being signed. Kordt considered that unlikely, since the conference appeared set to ratify what Britain and France had already offered Hitler. Hartmann's answer rested on the distinction between postponement and cancellation: Hitler had delayed mobilisation, not abandoned it.

At Munich, Wilson's account showed that the same pressure remained in force. Hitler demanded that the evacuation process begin by Saturday and watched the clock against the twenty-four-hour pause. Thus the threat operated through more than the prospect of military invasion. Its deadline narrowed the choices of the British and French leaders, gave force to Hitler's demand, and made the German opposition's opportunity depend on a decision that could be postponed as well as issued. The temporary reprieve changed the timing of the crisis, but left its underlying danger intact.