If the ongoing collapse of Iraq seems familiar you might be thinking of how North Vietnam took over South Vietnam when the US pulled out. Similar situation to what is going on right now in Iraq and will probably happen later this year (or perhaps next year) in Afghanistan.
The US finds itself again in the position of having come out on the losing side of another civil war. Perhaps we are just jinxed or perhaps we don't learn from history and we are doomed to keep repeating the same failed 'nation building' policy over and over.
We can't rewrite history, whether it is Vietnam or what has gone on more recently in Iraq. What we need to do now is deal with what we have.
Let's establish some 'home truths': Since the founding of their religion the Shia and Suni branches of Islam have been at war with each other, this isn't going to change, each side views the other as being blasphemers and apostates of their religion.
They simply hate each other, always have, probably always will.
Put bluntly, while Muslims are killing each other they are not killing us. A harsh statement but how is it wrong?
Demonstrating that even a comedian can get it right now and then and when speaking about the Syrian conflict on the Tonight Show of 6/19/13 Jay Leno said: 'These 2 enemies of ours are fighting each other - why are we involved?' Possibly the only things that we (the West) have going for us in the coming 40 years is that Islam is not one great monolith. It is fractured and may well come apart without any necessity for conflict with the West.
In the short term I suggest we not further involve ourselves in Islamic countries.
We have not done a very good job so far, why would we believe that we will do better with further meddling?
Just take a deep breath and step back and let them keep killing each other.