Now considering middle-east. Suppose we should send troops there and remove Daech and Assad, what should we put instead?
-Another dictatorship? What is the difference with Assad aren't we going back to the point where we started? And putting dictator like we did in Afghanistan leads nowhere since as soon as US troops will withdraw the population will remove Ghani from power
-A democracy? Every time people in middle-east had the choice to elect their leader they choose islmamism.
Iran gave full power to Khomeiny, Egypt elected muslim brotherhood, Gaza voted Hamas, AKP taking power in Turkey, Tunisia elected Ennahadha. So it won't change much, the council of Charia will take power but by democratic means, but we will have spend millions in sending troops there and alienated most of the population.
Then the west will have two choices, try to overthrow him like interventionniste-dummie like you, love to do. And we are back to dictatorship, civil war, and bombings and terrorists attack like in Egypt.
Or we let them be, and either people keep their elected leader like in Iran, which doesn't cause any terrorist attack anymore as either people there are content with their situation either they are angry but against their governement (and not the west). Even if Iran like to runt, they don't do much.
Or people eventually get tired of islmo-politic and stop supporting it, like Tunisia where Ennahadha is losing power, and the desperate terrorist attacks there don't have the support of the population anymore. Finally with the work of time and peace, you end up with a situation like Senegal.