This was a British deception and cover plan for operations to support Turkey and pin German forces in the Balkans (January/March 1943).
Created in the middle of January 1943 by Colonel Dudley W. Clarke’s 'A' Force deception organisation in the Middle East, and intended to succeed and intensify the effect of 'Warehouse, the 'Withstand' plan was designed to exaggerate, in the eyes of both the Turks and the Germans, the Allied perception of the Axis menace to Turkey, so prompting a possible Allied pre-emption. This, the plan hoped, would help to pin German forces in the Balkan area and, it was also hoped, encourage Turkey to consider joining the Allied side. The 'story' promulgated by the plan was that the Allies anticipated a German invasion of Turkey across Bulgaria’s land frontier with Turkey, and intended to divert German forces from such an operation by an invasion of Crete and the Peloponnese islands group in the southern part of the Aegean Sea, and by the strengthening of their forces in Iraq and Iran.
The Middle East Defence Committee disapproved of any concomitant efforts to deceive the Turks themselves, so the plan was simply merged into the existing 'Warehouse'. The combined plans were implemented by physical methods along the Turkish/Syrian frontier and by intelligence means. Yet again a British dummy tank regiment was displayed, along with real troops, from January to May.
The operation was very successful in deceiving the Germans, and peaked on 2 March when the German navy cancelled all leave in the Aegean Sea area in the expectation of imminent action, and again on 29 March 29 when Generalfeldmarschall Wilhelm Keitel, the chief of the Oberkommando der Wehrmacht, issued a order continuing to 1 June the secret arrangements with the Bulgarians to meet a British, US and Turkish invasion. The undertaking also confirmed the vital importance of the 'Cascade' order of battle deception in making such threats plausible. On 4 February the Fremde Heer West (foreign armies west) intelligence department opined that currently the British forces available in the Near East were certainly sufficient for a landing in Greece and for a partial occupation of that country. The Fremde Heer West's estimate of the forces required for an amphibious assault on Crete was 4.5 divisions, with another 4.5 divisions ready to cross from Syria into Turkey.
In March, with the new general policy approved, 'Withstand' was formally incorporated into an updated version of 'Warehouse', and suggested that the Balkans would be invaded from the Middle East early in summer, in the form of synchronised landings in western Crete and the Peloponnese. This was supposedly expected to persuade Turkey to join the Allies, who could then bypass the Dodecanese islands group and move air forces and two armoured divisions through Turkey against Thrace and to support Turkish operations against Bulgaria.
The plan was never fully implemented, for discussions in March at General Dwight D. Eisenhower’s headquarters in Algiers, stipulated that the planning and implementation of the 'Husky' (i) invasion of Sicily needed something more comprehensive. 'Warehouse' was therefore merged into the Mediterranean-wide 'Barclay'.