Syria had a population of about 20 million in 2010. Since then 250,000 have been killed mostly by Assad (since it has been around Daesh estimated to have caused 5% of Syrian civilian deaths), 10 million (yup half the population) have been forced out of their homes, 5 million are living in camps in Turkey, Jordan and Lebanon and perhaps another 1 million have fled to Europe. But Assad poses no threat to us.
It seems to be impossible to get a figure for total deaths caused by Daesh, in the low tens of thousands possibly. They obviously pose a threat to us.
Saddam killed up to 1 million of his own citizens. Despite what Blair said he never posed a threat to us.
We fought a war in Afghanistan to try and get rid of Al Qaeda and succeeded in merging them with the Taliban and making Pakistan even worse than it was already. Al Qaeda posed a threat to us.
I can't find any figures on how many people Gadaffi killed, not so many I guess, but he was a major sponsor of international terrorism and the US bombed Libya in reprisals on a pretty regular basis. Blair had tea in a tent in the desert with him. Despite the threat that he posed us.
I have no problem with bombing them all to ****, but our policies have no coherence or consistency. We let Gadaffi stay in place for 40 years even though he was organising attacks on us. We declined to help the forces trying to get rid of Assad. We fought two wars against Saddam, but even after the first one we let him continue terrorising his own people. We throw money at Pakistan, even though they don't cooperate with us and are obviously taking the piss.
We **** up the end game every single time, without fail.
So I would support the bombing of Daesh in Syria, Iraq and their strongholds in Sinai and Libya as well. The world is better off without them, even if they weren't a threat to us. Because they are disgusting people, it's an insult to medieval people to call them medieval. It may reduce the threat to us a little, but as far as I know the terrorist attacks that have happened here have all been carried out by British Muslims, and I would expect that to continue into the future, whether they are aligned with Al Qaeda, Daesh or any of the inevitable successor nutter death cults. History means that fairly or unfairly we will always be a target for Middle Eastern anger. We can withdraw from the world entirely, close our borders, avoid alliances, but this would still be the case.
What I don't understand is what drives our current and past policies - humanitarianism? Self interest? Supporting our allies? Self protection? I don't expect morality (a moveable feast anyway) to play a role, but a bit of integrity would be handy.