This weekend sees America poised to strike Syria. The President's national security team are huddled in the Situation Room, reviewing targets and war-gaming different outcomes.
Five US warships, armed with Tomahawk cruise missiles, are in position in the eastern Mediterranean. The Admirals are waiting only for their Commander-in-Chief to issue the order.
But at that point the certainly ends and we enter an extraordinarily tense guessing game. For what will President Assad do in response?
Will he feel suitable chastised and return to using only conventional weapons, realising the price he has paid for the August 21st chemical attack?
Or will Assad lash out at Israel or even attempt to take on the American armada over the horizon?
We will learn a lot in these next few days about Obama too. What is his appetite for risk? The reluctant warrior has decided that he must intervene in Syria but will he go for a warning shot or a major assault?
We are about to find out.