Read the full article on The National Interest.

Last night Donald J. Trump became the third consecutive U.S. president to ensure that his successor will also need to wage war in Afghanistan. This is justifiably frustrating to the American public, but unfortunately appropriate to the threats at hand.

As each of his predecessors previously concluded, often to their chagrin, the risks that withdrawing from Afghanistan poses to U.S. interests outweigh the costs of continued military engagement there. Those interests center around the Salafi jihadist terrorist organizations who seek to carve out sanctuaries from which to conduct external attacks on Americans at home and abroad. Indeed, if organizations such as Al Qaeda and the Islamic State were to magically disappear from Afghanistan tomorrow, the United States would have no vital national-security interests there at all. And any remaining diplomatic and humanitarian interests there would hardly merit U.S. military operations, much less the continuation of the longest war in U.S. military history.

But as things stand today, nothing would entail a more convincing victory for these organizations than to successfully drive out the United States, raise their flag over some remote corner of Afghanistan and direct external terrorist operations against Americans from there with impunity. It is this scenario that President Trump will fight to prevent, just as Presidents Obama and Bush did before him. And since these terrorist organizations—or whatever future groups later arise there to take on the Salafi jihadist banner—are not likely to disappear from that country within the lifetime of the Trump administration, the next U.S. president is likely to bemoan the hand dealt there, just as Trump does now.

So while Trump’s rhetoric suggested a sharp break from his predecessor’s approach, the basic parameters of U.S. policy will remain largely consistent.