As the Trump transition team looks to roll back Barack Obama’s second-term tsunami of executive orders and regulations, and Republican leaders in Congress prepare to repeal Obamacare, the outgoing president’s legacy seems to shrink daily. But one effect of eight years of Obama won’t soon vanish: He’s done more damage to American military power than his successor can repair. It’s not simply that Obama tried to end U.S. involvement in the Middle East by unilaterally withdrawing from Iraq, conducting a phony surge in Afghanistan, and failing to respond to the civil war in Syria. It’s not just that Obama did …