One take on it as that actually the US don't give a toss who is...

One take on it as that actually the US don't give a toss who is the enemy or not, they just want to ensure there is no 'stability' in the middle east.
1) The middle east is islamic and islam prohibits the charging of interest on loans. Any stability would potentially provide an educated society in idealogical opposition to the central bank FIAT model the world currently is operating under. Syria currently fits the bill. Libya fitted the bill.
2) Stability in the middle east would provide nations the choice about whether sell their oil and gas to the US OR China or India, depending on who pays the most. It also provides them the choice to sell it in something other than petrodollars.
3) Stability in a country would provide an environment ripe for investment. Countries that are stable could receive investment from China and or Russia or India to build pipelines to those countries. And we can't have that.

I am currently reading The Grand Chessboard by Zbigniew Brzezinski. He is the American who has influenced/dictated all US foreign policy since the 70s (to every government, Rupublican or Democrat) and still does. It puts many things into perspective.

Needless to say I have huge sympathy for the innocents in all the middle eastern countries who find themselves caught up in this.