Sometime the message will get through to Western leaders  that if you attack Muslims, or any other group, you can expect retaliation. For example the West set up Israel with the best of intents except it meant taking land from Arabs/Muslims. The Arabs retaliated against embassies in Africa, a US Naval ship, the US responded attacking a factory in Khartoum and caves in Afghanistan. Then the  Arabs responded with 9/11. It is very clear that if the west attacks Arabs,  the Arabs will respond. Immigration control will do little until the west stops attacking Muslims.