It is never easy to write about foreign affairs, especially on matters of war and peace. The analyst who sits on the sideline does not, and should not, have access to the key information on which to make informed judgments about the most difficult decision that faces any President of the United States: When and how to use force on foreign soil.

The stakes are high and the events are often outside the control of the U.S. Worse still, the consequences of mistaken intervention overseas can prove disastrous to American armed service members, whose lives are put in unnecessary danger, to the standing of the United States in the eyes of the world, and to the local populations who are the intended beneficiaries of American action. At the very least, there ought to be a presumption against committing American forces in the absence of a direct and immediate military threat to the United States and to its treaty partners.

Yet that presumption is not absolute: Sometimes, the dangers of standing aside are as great as, or even greater than, those of getting involved. Both World War I and World War II stemmed in large measure from moving too slowly in the face of serious danger. On November 7, 1916, Woodrow Wilson narrowly beat the Republican Charles Evans Hughes by invoking the slogan, “He kept us out of war,” only to lead the United States into the war against Germany six months later on April 2, 1917.

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