740.0011 European War 1939/15111
Memorandum by the Under Secretary of State (Welles) to President Roosevelt
The item here attached77 is an excerpt from Ambassador Grew’s diary. This entry was written on or about March 30, 1941. It deals with strategy in connection with our relations with Japan and it emphasizes the necessity of holding our position in the Far East.
In it, Mr. Grew, having emphasized the point that “the future safety of the United States [et cetera]78 are inextricably bound up with the safety of the British Empire”, lays it down as “axiomatic that we cannot in our own interest and security afford to see Singapore fall”; and, having reaffirmed an opinion which he has repeatedly expressed in other contexts, that it is “a question not of whether we must act but when”, proceeds to state why.
He points out that Japan “may not go directly all out in a head-on attack on Singapore; that more likely it would proceed by a nibbling process; but that the southward advance is aimed at Singapore” and “every step brings the Japanese nearer Singapore and constitutes an increasing threat to that essential base”. He affirms the thesis that “the risks of not taking positive measures to maintain our future security in the Far East …79 are likely to be much greater than the risk of taking positive measures as Japan’s southward advance proceeds [whether by nibbling or with a direct thrust]”.78 And he expresses the view that “we shall avoid war with Japan if Japan once becomes convinced that we mean business and that a Japanese attack on Singapore would inevitably result in war with the United States”.