"[Y]ou can't meet a general anywhere in the Pentagon who believes there is a military solution to the Afghan war," Sen. Rand Paul (R–Ky.) mused in a recent radio interview. "That's the main question I harangue them with when they come up to Capitol Hill to testify before our committees: I say, 'Is there a military solution?' And they all admit there is none. There's been mission creep that's now nation building, but they all admit no military solution."

So why are we still fighting America's longest war? Why continue our military intervention in Afghanistan after nearly two decades, when there is no prospect of anything resembling success?

The question becomes all the more pressing given that key players in the Trump administration appear to agree with the Pentagon consensus Paul describes. President Donald Trump himself has repeatedly expressed a desire to end the war, and he ordered a partial reduction in the U.S. troop presence in Afghanistan in December. His current secretary of state, Mike Pompeo, has acknowledged that peace in Afghanistan will have to be achieved via Afghan-led negotiations, not U.S. military action. Former Defense Secretary James Mattis said the same, arguing last year there is no "military victory" available to the United States. Rather, he said, "the victory will be a political reconciliation."

Paul proposed three explanations for this gap between word and deed. The first is a personnel matter: "The problem is that several of [Trump's] advisers that he has appointed don't necessarily agree with him" about getting out of Afghanistan, Paul said. "So they either countermand his sentiments or talk him into delaying actually ending the war."

Trump's national security advisers have been particularly pernicious in this regard. First the office was occupied by H.R. McMaster, who endorsed "state-building in places like Afghanistan and Iraq," and consistently seemed to steer Trump toward unjustifiably aggressive foreign policies. The seat is now filled by John Bolton, whose complete and reckless hawkishness is detailed anew in a lengthy New Yorker profile this week. "Bolton is a hawk," Trump reportedly said of his adviser shortly before hiring him. "He's going to get us into a war." At the very least he's managed to keep us in half a dozen, and it is unlikely Trump will be able to deliver on his more sensible foreign policy impulses so long as voices like these have his ear.

The second problem Paul identified is that "there are still a number of people [in Washington] who are of what I call the Vietnam village strategy—take one more village and we'll get a better negotiated settlement." Pompeo certainly seems to be of this ilk, describing the U.S. position in the Afghan peace talks as one of ensuring the Taliban realizes "they can't win on the ground militarily."

While it is true the U.S. military can skirmish with the Taliban forever, this is no argument for prolonging the war. Pompeo is no doubt right that Taliban leadership understands it cannot trounce the most powerful military on the planet, but that hardly means continued U.S. intervention has the Taliban cornered. On the contrary, the group has been resurgent in recent years, gaining control over larger portions of the country even after massive and costly U.S. military efforts. And if that's the case, as Paul said, "I don't want to send my kid, your kid, or my nephew to Afghanistan—because if there is no military solution, what is one more death going to do over there?"

It is utterly indefensible to spill more blood and treasure to, at best, maintain a stalemate. Negotiations, already underway, will proceed with or without U.S. boots on the ground. If anything, American military exit might imbue the talks with a fresh sense of urgency, prompting necessary compromises neither side is presently willing to make.

The third delaying factor is how the mission has morphed. "[W]e just need to acknowledge that our original mission was to go after those who plotted or attacked us on 9/11," Paul said, "and there's frankly none of them left….We're [now fighting] forces that are associated with forces that are associated with forces that are associated with somebody else. It's so tangential to have any link to 9/11 that it really doesn't exist."

That calls into question the legality of this evolving intervention, since the original Authorization for Use of Military Force specifically cited the 9/11 attacks. It also raises serious practical and strategic concerns. It serves the interests of neither the U.S. nor local populations for Washington to perpetually police the world, moving endlessly from one parochial fight to another, offering military solutions to problems that need political and diplomatic resolutions orchestrated by the people whose lives they'll affect.

Each of these obstacles—bad advice in Washington, a needless maintenance of stalemate, and strategically reckless mission creep—can and must be overcome if Trump really intends to make good on his promise of a new direction for American foreign policy. There is no military solution to be had here; it is time to simply come home.