Explainer: Why is Trump pushing to ‘retake’ Bagram Air Base?

Bagram Air Base -- once the beating heart of America's war in Afghanistan -- is back in the global spotlight.

US President Donald Trump has called for it to be brought back under American control, warning that if it isn't, "bad things" could happen.

But is this really about counter-terrorism? About checking China? Or is it simply a show of American strength? Can Washington actually pull this off without reigniting the war it spent two decades trying to end? And how will the Taliban and the rest of the region respond?