I don't think that the American public knows what's going on in Syria.

When the missile strikes took place in 2017, only one person in my regular life talked about them, and she didn't know why they were ordered.  The American media's discussion of that situation was so focussed on the interaction between the White House and Congress that she thought that President Trump had ordered an arbitrary attack on Syrian civilians.  She had no idea that the strikes were a response to the Assad regime's illegal use of chemical weapons.

If the American public knew that genocide has destroyed Syria, and that the country has been bombed into dust by its own leader and his allies, I don't think that the public would object to the United States and our allies doing what is necessary to dislodge Mr. Assad