America's foreign policy is built upon simplistic and childish assumptions.
There are many ways to demonstrate this, but the most obvious and direct way is to ask the question, "...and then what?"

In many ways this is the same situation as 2003. Saddam was a bad guy. Assad is a bad guy.
Saddam used poison gas (that we sold him). Assad may have used poison gas.
If our foreign policy is as simplistic as "He's a bad man who did bad things, so he must be punished", then Trump's airstrikes on Syria and Bush's invasion of Iraq make perfect sense. End of story.
We're the good guys and we kicked ass. Message sent, but by dropping bombs instead of wearing pink hats.

However, if you ask adult questions like "What do you want to achieve? And how do you plan to achieve it?" then all of a sudden the stupidity and shortsightedness of our virtue signaling becomes apparent.
If you ask those two questions then you are immediately confronted with the problem that we are bombing both sides of a civil war (Assad on one side and ISIS/al-Qaeda on the other), and want the destruction of both sides.
This is obviously total insanity.

There is no possibility of achieving this without a full-scale invasion and occupation of Syria, and even then achieving those objectives are as unlikely as they were in Iraq.
Just bringing down Assad mean empowering al-Qaeda, the group that committed 9/11.
Faced with this unsolvable dilemma, Americans retreat into childlike fantasies that require inventing "moderate" rebels that will suddenly appear out of thin air to provide us a "solution" to this problem.

That doesn't even address the complication that we didn't have to face in Iraq: Assad has important allies. He isn't isolated and alone like Saddam.
Russia may or may not be ready to confront us militarily, but even the childlike, liberal interventionist should be able to see that their virtue signaling isn't worth the risk.
Even if Russia backs down, Iran won't. And Iran will be a much, much tougher nut to crack than Iraq was.
Suddenly that signaled virtue of the liberal interventionist has a high cost. Maybe they can understand why their moral outrage doesn't impress people in the middle east.

What will it take to get the neocon/liberal interventionist to see the madness of their ways? I have no hope of it happening, because they failed to learn anything from Iraq, Libya, and Afghanistan.
They are simply too stupid to learn. Their voices must be held underwater until they stop kicking. Otherwise they will destroy the world.

“On Syria, ladies and gentlemen, we are going to have to determine what is the end state we want. This war needs to be ended as rapidly as possible. That’s the bottom line. But if the Americans go in, if the Americans take leadership, if the Americans take ownership of this, it’s going to be a full-throated, very, very serious war. And anyone who says this is going to be easy, that we can do a no-fly zone and it’ll be cheap, I would discount that on the outset.”
“We need to be very clear about our military end state, contributing to what political end state. Otherwise, you’re liable to invade a country, pull down a statue, and then say, ‘Now what do we do?'”
“We all want to do something to stop this. But the desire to do something, the intention to do good, does not take the place of pragmatic, ‘What is possible?’ We have no moral obligation to do the impossible and hawk our children’s future because we think we just have to do something.”
Mad Dog Mattis, 2013