noun \ˈkä-səs-ˈbe-ˌlē, ˈkā-səs-ˈbe-ˌlī\
plural ca·sus belli \ˈkä-ˌsüs-, ˈkā-ˌsüs-\
Definition of CASUS BELLI : an event or action that justifies or allegedly justifies a war or conflict
Origin of CASUS BELLI
New Latin, occasion of war
First Known Use: circa 1841
June 26, 1950 1200
Throughout the morning the Secretary of State, the Secretary of the Army, and the military chiefs were in conference at the Pentagon. [note]
[About noon in Korea] This opening thrust was quickly deflected, and the discussion properly turned to the larger picture: Stalin and the Kremlin. What did Stalin's decision to resort to "raw aggression" portend? Bradley speculated. He did not think Stalin was "ready" for global war; the Kremlin was probably "testing" America's spiritual resolve to its containment rhetoric. However, Bradley went on, this major escalation in the cold war was a "moral outrage" which the United States and United Nations could not countenance. To knuckle under in this test, he said, would be tantamount to "appeasement." One act of appeasement could lead to further acts and hence almost inevitably to global war. "We must draw the line somewhere," Bradley concluded, and Korea "offered as good an occasion for drawing the line as anywhere else.[3-19]
All fourteen men present, including most emphatically President Truman and Dean Acheson, were of like mind. All the prior policies set forth in various position papers, reached after years of careful study - that South Korea was of little strategic importance and should not be a casus belli - were summarily dismissed. On June 24, 1950, South Korea had suddenly become an area of vital importance, not strategically or militarily (as Acheson would write in his memoirs) but psychologically and symbolically. Stalin had chosen that place to escalate cold war to hot war. The line would be drawn. South Korea would be supported, not because its conquest would directly threaten America's vital interests but because a failure to meet Stalin's challenge there would be so morally derelict it might fatally damage America's prestige and lead to a collapse of the free world's will to resist Communist aggression in places that really counted.
The conferees next wrestled with these questions: How much help? What form should it take? There was a stingy approach to the problem: Minimize, not maximize, the commitment. Finally, they agreed on the following steps, to be carried out with utmost haste under the "guise of aid" to the UN, which that day had condemned the NKPA invasion and invited "all members" to help the ROKs.
MacArthur would proceed (as he was already doing) with sending "ammunition and equipment" to the ROKs in order to help "prevent the loss" of Sŏul.
MacArthur would rush a "survey party" to South Korea to find out what other military aid the ROKs might need to hold Sŏul.
MacArthur would provide "such naval and air action" as was necessary to prevent the loss of Sŏul partly under the guise of ensuring "safe evacuation of United States dependents and noncombatants."
The Navy's Seventh Fleet, then at Subic Bay in the Philippines, would proceed to Sasebo, Japan, to augment MacArthur's thin naval forces.[3-20]