Although the Iraq War sucked all of the oxygen out of America's national discourse, it's the war in Afghanistan that has been America's longest war, lasting for over 18 years.  One of President Trump's campaign promises was to end that endless war, and, on Friday, he took the first step in making good on the promise: the U.S. is on the verge of entering into a "reduction in violence agreement" with the Taliban that is a predicate to a U.S. troop withdrawal.

Shortly after 9/11, U.S. intelligence learned that Osama bin Laden was hiding in Afghanistan as a guest of the Taliban.  When the Taliban refused to extradite bin Laden, in October 2001, the U.S., along with Great Britain, launched "Operation Enduring Freedom."  That war is now over 18 years old.

During those 18 years, over 2,000 Americans have died, as well as over 1,000 troops from allied nations.  Almost 23,000 Americans were wounded, as were over 2,000 British troops.  In addition, almost 4,000 private contractors died, and at least 15,000 have been wounded.

In return for all this blood, America did receive a significant benefit: Afghanistan is no longer a secure base for training and housing anti-American terrorists.  That's not to say that the Taliban won't again play host to Islamist jihadists.  For now, though, that goal is achieved, and, unless America wants to have a permanent military presence in Afghanistan, it's time to go home.

For some time now, secretary of state Mike Pompeo and defense secretary Mark Esper have been meeting with the Taliban and with Afghan president Ashraf Ghani to negotiate an American troop withdrawal.  This is a delicate business, because the last thing America wants is a repeat of Obama's abrupt withdrawal of troops from Iraq.

Obama's approach created a vacuum that ISIS — which Obama originally dismissed as a "J.V. team" — quickly filled.  Between Obama's embrace of the Arab Spring (including helping to depose Egyptian president Hosni Mubarak, an American ally) and his cavalier attitude toward ISIS, the entire Middle East was destabilized, which has helped destabilize Europe as well.  With luck, though, the proposed plan will have a better outcome.

For now, the parties are just taking preliminary steps toward ending the war:

The tentative agreement would lay the groundwork for a larger troop withdrawal:

The United States and Taliban reached an agreement on Friday to reduce violence for seven days, which could open the door to the two sides signing a larger peace deal reached last year, according to a senior State Department official.

That larger deal would require U.S. forces to begin to withdraw, in exchange for a Taliban commitment to not allow Afghanistan to be a safe haven for terrorism and to sit down with other Afghans for peace talks — two commitments critics are skeptical the militant group will follow through on.

[snip]

A Taliban source told ABC News the reduction would begin on Feb. 22, with plans for the two sides to sign the larger agreement on Feb. 29 and Afghan national peace talks to begin March 10.

While it's not a full ceasefire, the reduction is nationwide and includes Afghan government forces, not just the U.S. and Taliban. The language is also "very specific," the official said, including prohibiting roadside bombs, suicide bombs and rocket attacks.

The U.S. military will monitor the reduction and use a hotline directly to the militant group, as well as the Afghan government, to raise any violations or other issues.

A withdrawal from Afghanistan will be another step in advancing the Trump Doctrine.  This doctrine represents a retreat from the Wilsonian foreign policies that have dominated the world since 1917.  Back in 1917, to justify having America enter WWI on the British side, Wilson formulated a doctrine saying it was America's responsibility to make the world safe for democracy.  We have been doing that for 100 years.

Trump's doctrine, however, is that we have to make the world safe for America.  This does not mean territorial expansion à la Hitler or Tojo.  Nor does it mean retreating into fortress America and letting the world go to Hell in a handbasket.

The Trump doctrine means, instead, determining whether foreign military involvement will confer a benefit on America.  In this, it is the opposite of Obama's foreign policy, which seemed to insist that America, to show her virtue in any overseas initiative, could engage only in actions that worked to her detriment or, at the very least, did not confer a benefit on her.

A strategic withdrawal from Afghanistan, a country in which we've stayed long after we achieved a narrow, targeted victory, is an excellent idea.  There is no longer a benefit to us in staying in Afghanistan, although one would hope that the military and American intelligence will keep an eye on things to ensure that another bin Laden doesn't take root there.