Well, is Uncle Sam not a modern charity man that gives gifts to poor children?
The Americans have interest in Syria because the country hosts Tartus as the sole Russia naval base outside the former Soviet Union. The other semi permanent one is Camranh bay. Destroying the naval base means weakening Russia military power. besides it benefits the turkey. Why Turkey? Because it is the only Muslim country in the world that has a respected conventional army. The other is nuclear armed Pakistan. The rest, from poor Indonesia to rich Saudi Arabia is negligible. Look, how the Arab armies performed against Israel. Terrible is an understatement.