There isn't a recent west world foreign policy, the west has been doing the same stuff in the east for the past 50-60 years. It's mostly about profit, the same with the drug war, the military industrial complex has been causing conflict around the world since not long after the end of WW2. Military production made some incredibly rich people/companies which gave them a lot of power during WW2 in America, then the war stopped, the profits came in but they were effectively time limited and not increasing. They wanted more conflict so they pushed for conflict and war wherever they could find it. Vietnam... "the commies are trying to take over the world"... except they weren't. Draft people in, use lots of military equipment, funnel billions and billions of tax revenue into military companies.
They've been meddling in the east this whole time, from establishing Israel which was a guaranteed problem for the foreseeable future, to training groups of fighters to fight back against Russia, to using Iran to start a conflict with Iraq, to dumping Iran and backing Iraq when their interference in Iran helped inspire an uprising to their 'friendly' government in Iran which was hijacked by the religious groups who hated the modern/liberal push the country had taken who took an anti west involvement stance when they seized power. Then Iraq was backed, etc, etc. This has been going on for generations.
We (the 'west' in general but the USA/UK being the most involved really) have been incubating hate, ignorance and holding back the middle east for several generations to the point where everyone over there has lived under the threat of war or conflicts and usually the consequences, injury, dead family members, kids called in collateral damage.
This isn't recent, it's not close to recent. Look at how Iran was before the uprising, it was pretty liberal and moving forward, education was pushed and people were moving away from religion as the West did so with more education. The majority of the middle east would have continued to develop and move forwards, more educated, less religious and less extremist without being constantly knocked down with infrastructure destroyed in needless conflict. There is no profit (for these specific companies and people with monumental influence and power) in peace, so they've been making sure for decades that there will be continued conflict and terrorist attacks just generates more excuses to go back and bomb them again, creating the next generation of terrorists when the reactionary bombing kills another parent, sibling or child.
Terrorism is vile, targeting a concert that would have a younger audience is despicable, but you have to realise that people profit from this, those people have been meddling over their on purpose for a very very very long time and you can't cause conflict across an entire region for 60+ years and expect not to create a monumental amount of hatred from those people.
