The government of the United States has on frequent occasions stated its conviction that only through international support of a program of order based upon law can world peace be assured.
This Government, founded upon and dedicated to the principles of human liberty and of democracy, cannot refrain from making known this country's condemnation of the acts which have resulted in the temporary extinguishment of the liberties of a free and independent people with whom, from the day when the Republic of Czecho-Slovakia attained its independence, the people of the United States have maintained specially close and friendly relations.
The position of the government of the United States has been made consistently clear. It has emphasized the need for respect for the sanctity of treaties and of the pledged word, and for non-intervention by any nation in the domestic affairs of other nations; and it has on repeated occasions expressed its condemnation of a policy of military aggression.
It is manifest that acts of wanton lawlessness and of arbitrary force are threatening world peace and the very structure of modern civilization. The imperative need for the observance of the principles advocated by this Government has been clearly demonstrated by the developments which have taken place during the past three days.
Franklin D. Roosevelt, State Department Statement on the German Partition of Czecho-Slovakia Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/209461