Since the end of World War II, the United States has been involved various regional wars and conflicts. Success has been mixed at best. Korea ended in a stand off but South Korea was saved. Vietnam ended as a failure. The Iraq and Afghanistan wars have not accomplished their aims.
But there is one exception.
The war against Isis ended with Isis losing their territory and reverting to an underground terrorist group instead of a government by terror of large areas of Syria and Iraq. Why did this happen?
The answer is simple. The Kurds of Syria fought Isis with everything they had. Their fight in the siege of Kobani shamed the Americans into helping them. Read the book Daughters of Kobani about the incredible Kurdish women warriors. Eventually the US provided air support, intelligence, and other help, which tipped the scales in the Kurds favor. Thanks to the Kurds successful resistance, the Iraqis, especially Shia militia that hated Isis, started to be more effective.
Contrast the Kurdish efforts to other US allies in regional conflicts. The South Vietnamese for the most part were never very effective. When Isis made their first offensive push in Iraq, the Iraqi Army abandoned Mosul and large amounts of US supplied equipment to a much smaller Isis force. Now in Afghanistan, an Afghan army that is 3 times the size of the Taliban force and that has an air force and more heavy weapons is not putting up any effective resistance to the Taliban. History is filled with examples of smaller military forces defeating much larger armies who lack the motivation to fight. I have always wondered if the Vietnamese and the Afghans were just waiting around for the Americans to take care of everything, and lost any sense of their own initiative. Corruption and ineffective leadership also sapped the will to fight.
The Kurds did not wait for the Americans, they fought hard against Isis right from the start. They had good reason to fight, Isis was a mortal danger to them. This is a clue for any American government that is tempted to get involved in a regional conflict. If you have allies who have demonstrated motivation and effectiveness, success is far more likely. If America has to send in large ground forces, that probably means there are no effective allies and success is unlikely. If American soldiers are kicking down doors and arresting people, and have to worry if anybody on the street is an enemy fighter, then success is unlikely. If the enemy lives there, the enemy will outlast us. if the enemy is a different culture and religion, long term success is impossible. Only strong local allies make success possible.
It is clear that most Afghans don’t like the Taliban. But their government is weak and corrupt, and for the most part they don’t seem to be able to fight the Taliban. The US cannot help them if they won’t help themselves.
For the most part, these regional conflicts have very little to do with US national security. History has shown that the Vietnam War was not needed for US security. The Iraq war did nothing for our security either, it was a mistake based on the egos of the neocons. When the US invaded Afghanistan after 9/11, they should have withdrawn most of the troops after the Taliban lost control and Al Qaeda was expelled. The US army, with a different culture and religion than the Afghans, could never have eliminated the Taliban. Only the Afghans themselves can eventually deal with that problem.
A question we have to answer is whether the United States should ever get involved in a regional conflict for humanitarian reasons. The Libya situation shows how hard this is to do successfully. If we ever want to do that, we need a strong local partner, such as the Kurds. Donald Trump’s abandonment of the best allies we have ever had in such a situation is shameful.