The legal significance of "nonbelligerency" does not
permit of much doubt ... the abandonment of a strict
impartiality demanded by the traditional law ...
served to give rise to the belligerent right of reprisal. (1)
BACKING INTO WAR
The years immediately preceding World War II found the United States in a state of national ambivalence. The horrible memories of the great war had not diminished, and the isolationism those memories nurtured expressed itself legislatively in the Neutrality Acts of 1935, 1936, and 1937. (2) These laws were more restrictive than international law required and their object was more than neutrality. The Neutrality Acts were intended to keep the United States clear of entanglements that might unwittingly lead to war. In taking this more restrictive tack, "The Neutrality Acts ... had not abandoned international law, they had only determined not to assert all possible rights under it." (3)
Valid concerns over the international situation as the world slipped ever closer to war eventually replaced the dominant domestic desire for isolationism. When war swept through Europe in 1939, the pendulum of U.S. foreign policy was swinging from isolationism to internationalism with a force that soon proved irresistible. Domestic politics and public opinion combined to slow the United States' entry into the war as a belligerent but accommodated unneutral actions as a de facto "nonbelligerent."
The neutrality debate notwithstanding, in December 1939, the United States Maritime Commission issued orders to radio operators of U.S. flag ships to be circumspect in their discussion of the location of Allied shipping, (4) but back in October the President had authorized the reporting of any "submarine or suspicious surface ship" in "plain English" by the ships and aircraft of the U.S, Navy's neutrality patrol. They worked throughout the American Neutrality Zone established by the Declaration of Panamas to keep belligerent ships out of an area that reached up to 300 miles from the coastline of the Americas. Units on patrol were also required to maintain contact with these vessels as long as possible. The effect of this order was to alert nearby British merchant ships to the presence of this threat. Because the reports were in English, it also provided easy to use locating information, adequate for British warships to intercept and engage their enemy's ships and submarines. Further, while the United States avoided reporting Allied vessels, citing the danger of being considered unneutral under prize law, "submarines and suspicious ships" were reported and tracked in de facto cooperation with the British.
Secretary of State Cordell Hull asserted, "International law ... does not recognize any intermediate status between neutrality a n d ... belligerency." (6) That being the case, into which category did the Secretary place the United States? The implication is the administration was consciously and purposefully acting at variance from what it perceived the law to require. It could also be that there was a major disconnect between the Secretary and the President over which policy options should be considered appropriate.
In May 1940, when German victory on the Continent of Europe seemed almost certain, Prime Minister Churchill appealed to President Roosevelt, saying "You should proclaim non-belligerency, which would mean that you would help us with everything short of actually engaging armed forces." (7) While "non-belligerency" had no legal definition, it certainly enjoyed a great deal of practice. Of course, practice without an intention to comply with the law is insufficient to produce law.
The United States never formally declared any departure from neutrality, but U.S. actions varied widely from the legal obligations of an impartial neutral. While never engaged at a level of intensity comparable to the combat ashore in Europe or Asia, the United States behaved in a clearly unneutral manner. …