This is the editor's letter in the current issue of The Week magazine.

A century ago this month, President Woodrow Wilson persuaded a reluctant nation to jump into the carnage of World War I. A major, anti-militarist movement had challenged the wisdom of sending America's young men to die on European killing fields over a dispute that was not ours, but the idealistic Wilson decided an intervention was necessary to make the world "safe for democracy." Our nation has been having that same debate ever since, from World War II through Korea, Vietnam, Serbia, and Iraq. Less than 100 days into an "America First" presidency, the intervention dilemma is back. President Trump launched a barrage of 59 Tomahawk missiles last week after being moved by grotesque images of Syrian children dying in a chemical gas attack. Now his administration is warning North Korea's provocative Kim Jong Un that he, too, may suffer the new sheriff's wrath.

Every war launched on idealistic principles, we have learned, yields unintended consequences. Toppling the tyrant Saddam Hussein shattered Iraq and destabilized the entire Middle East, and gave rise to the horrors of ISIS. But doing nothing in the face of mass slaughter can bring its own regrets. Bill Clinton has conceded he might have saved 300,000 lives had he intervened in Rwanda's genocide; Barack Obama's refusal to do "stupid s---" in Syria made us spectators to 500,000 deaths and a massive wave of refugees that destabilized Europe. Now a new president stands at a crossroads between isolationism and interventionism, having tasted the rewarding purity of a punitive missile strike against a tyrant who kills kids. With gridlocked domestic politics so frustrating, will Trump seek satisfaction abroad, as commander in chief of the world's mightiest military? As several previous presidents can attest, a righteous war can make a president more popular ... until it doesn't.