Cablegram 473 22 April 1941,
IMMEDIATE MOST SECRET
Your telegram 283 and Latham’s No. 26 to you. [1] On receipt of report regarding Singapore we made known to United Kingdom Government through Prime Minister [2] great importance which we attach to contemplated joint declaration by British Empire, United States and Netherlands East Indies that an attack on Netherlands East Indies or on British possessions in the Far East would be regarded as a casus belli by both the United States and the British Empire. You are no doubt aware that proposal to this effect was raised in conversation by Halifax [3] with Hull [4] on March 5th.
It is now understood that United Kingdom Government through Halifax and Winant [5] has taken steps to press in Washington for joint declaration in above terms. Desire you should make concurrently strongest possible representations on behalf of Commonwealth Government in same sense. In view of position Middle East regard matter as of extreme importance and urgency.
STEWART
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1 Sir John Latham, Minister to Japan, sent cablegram 184 of 13 April to Canberra and repeated it to Casey as no. 26. It is on file AA: A1608, A41/1/1, xx, together with Casey’s cablegram 283 of 14 April. Both cablegrams concerned a report that Japan would attack Singapore by sea within the next few days with twelve to fifteen divisions.
2 R. G. Menzies, then in London.
3 U.K. Ambassador to the United States.
4 U.S. Secretary of State.
5 U.S. Ambassador to the United Kingdom.
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[AA: A981, JAPAN 185B, i]