The global war on terror has redefined what constitutes failure.
At one time sending kids to die in a generation-long quagmire without end in a narcostate would unquestionably constitute failure.
That is the situation in Afghanistan today, but no one in politics or the news media bothers to point out the obvious.
The bar for foreign policy failure has been lowered to a back-breaking limbo champion level.

And yet, our policy in Syria has managed to get under even that low standard.
In Afghanistan our allies may be corrupt druglords, warlords, war criminals (aka the Vietnam Strategy), but at least we've been consistent with our allies.

In Syria, we've failed at managing even that.
Consider these headlines:

In Syria, militias armed by the Pentagon fight those armed by the CIA, LA Times, March 27, 2016

U.S. Military Battles Syrian Rebels Once Supported by CIA, Now Backed by Turkey, Newsweek, August 29, 2017

Why Are U.S. Allies Killing Each Other In Syria?, NPR, January 23, 2018

It's hard to think of a more convincing measure of failure than to put your troops into a civil war, illegally and without an AUMF from Congress, and then repeatedly befriend and arm groups that proceed to turn those weapons on each other.

Speaking of those weapons, we not only acknowledge that they went to groups that we didn't intend, but that we are so clueless that we would ask for them back even while we openly plan the destruction of said group.

And yet, that isn't the absolute lowest level of our failure. For that you must look at this article.

U.S. and Russia Allies Join Forces in Syria, But This Causes New Problems for Leading World Powers, Newsweek, February 20, 2018

Fighters supportive of the Syrian government, an ally of Russia and Iran, have entered a northwestern enclave of Kurdish control to help the U.S.-sponsored ethnic minority fend off a Turkish invasion. Both Washington and Moscow have attempted to discourage their partners from entering the battle, but local forces have so far ignored the leading international powers.
Following sporadic violence last week between forces fighting on behalf of Syrian President Bashar al-Assad and the Kurd-dominated, Pentagon-created Syrian Democratic Forces (SDF), the state-run Syrian Arab News Agency reported Tuesday that pro-Syrian government “popular forces” have arrived in Afrin to defend it against an offensive by Turkish and rebel fighters seeking to dislodge Kurdish control.

Let's break this one down:

Our allies, the Syrian Kurds, that we armed, are fighting alongside Iranian-backed Shiite militias, that we armed with M-1 tanks, eventhough we oppose them in Syria because they are defending the Assad government, which is a Russian ally, which we also oppose.

They are fighting against Turkey, our NATO ally, and an army of jihadists that is made up of former ISIS and al-Qaeda militants, that we oppose, although we also helped arm.

You can't make this stuff up.
Our ruling class is not just incompetent, but they are also so corrupt that they refuse to acknowledge their own obvious failure.