Their original rationale for intervention has long been exposed as another lie.
Remember that President Obama initially involved the US military in Iraq and Syria to "prevent genocide" of the Yazidis and promised the operation would not drift into US "boots on the ground." That was three years ago and the US military became steadily more involved while Congress continued to dodge its Constitutional obligations. The US even built military bases in Syria despite having no permission to do so! Imagine if Syria started building military bases here in the US against our wishes.
After six years of war the Syrian government has nearly defeated ISIS and al-Qaeda and the US-backed "moderates" turned out to be either Islamist extremists or Kurdish soldiers for hire. According to a recent report, the US has shipped two billion dollars worth of weapons to fighters in Syria via eastern Europe. Much of these weapons ended up in the hands of ISIS directly, or indirectly through "moderates" taking their weapons with them while joining ISIS or al-Qaeda.