The generals wonder: What took Mattis so long — and what happens now?

Pentagon-watchers have long wondered how long Secretary of Defense Jim Mattis could effectively fend off President’s Trump’s assault on America’s global leadership and network of alliances. A retired four-star Marine general, combat veteran and military historian, Mattis managed slow-walking retreats in the face of Trump’s transgender ban in the military, unnecessary “Space Force,” and the morale-sapping deployment of thousands of armed U.S. troops to the southern border to repel a rag-tag caravan of migrants. Each time President Trump publicly insulted and disrespected allies, Mattis dutifully countered with charm offensives to soothe their nerves.

Yet this week when Trump decided to ignore the advice of top advisers and order the surprise withdrawal of all U.S. troops from Syria, and roughly half of the 14,000 troops deployed to Afghanistan, Mattis found himself on ground from which there was no principled retreat. These orders went far beyond provocative Tweets, political posturing at the southern border or self-aggrandizing requests for a military parade. Rather Trump was reversing strategic policy in combat theaters with life-or-death consequences for close partners. And the commander-in-chief was doing so unilaterally, against Mattis’ advice and with little consultation or preparation with the U.S. military chain of command, causing potential havoc in the field. That helps explain why Trump’s tweet was met with a letter of resignation from Mattis.