In the years before D Day the overriding issue that determined if/when the invasion of France could take place was the number of landing craft available for the cross channel trip. Churchill had argued to Stalin during 1941 and 1942 that there simply weren’t enough LST’s (landing Ship-Tanks). When it finally decided that enough would be available in May of 1944 most LST’s that were being used in Italy were scheduled to be sent to England for ‘Overlord’. The Americans were vehemently against anything that might delay Overlord. The Americans even had to postpone an invasion in the Bay of Bengal in the East that Roosevelt had promised China. Those 15 landing craft from the East were sent to the Mediterranean to replace some of the 104 LST’s that were to be sent back to England for the Invasion but they were not scheduled to arrive in time for the Anzio invasion. Churchill argued to keep 56 LST’s in Italy for an extra three weeks in January. They needed 88 LST’s to land two divisions in the Anzio invasion in Italy which was to help liberate Rome. This was important in order to liberate the airfields just north of Rome which could then be used to bomb parts of Germany.

(Book – The Second World War – Winston S. Churchill)