More bombings, this time in Russia and Spain. Let's take a moment though before condemning immigrants and Muslims (the usual suspects in the 21st Century) and remember that terrorism first and foremost is about an agenda. Philosophies and motivations are secondary.
What do I mean? Back in the Cold War days, any number of terrorist groups operated espousing some Marxist philosophy (European and South American groups) or Maoist philosophy (Asian groups). Often though most were primarily anarchists.
Despite their philosophical rhetoric, no one really believed that being a Marxist or Maoist automatically made you a terrorist. Terrorists of the 20th Century were motivated to commit their acts of violence by those who funded their activities. In the examples above, this usually meant Soviet Union, Communist China, or Cuba. The US funded right-wing groups opposed to the left0wing groups and trained many of their leaders through the US Army School of the Americas (now known as The Western Hemisphere Institute for Security Cooperation, WHINSEC).
20th Century terrorists were therefore third party operatives of either the Western or Eastern governments that funded their activities. Then two terrorist attacks occurred to reshape this thinking.
The first was the bombing of Pan Am Flight 103 in 1988 by Libyan terrorists. The second was the bombing of the Word Trade Center bombing in 1993. These attacks targeted the US and were not backed by the Soviet Union but rather but and Muslim nation (Libya) and Muslim terrorists (Khalid Sheikh Muhammed, from Pakistan, planned the attack). Now with the Soviet Union out of the picture, Islam became the new reason du jour.
Intelligence agencies and the military especially went batshit crazy because it meant you would never have to prove a clear line back the the organizers, the way you would say with the former Soviet Union. Now you had to merely point out that the suspects were Muslim, better if you could also add "radicalized" into the narrative, and presto! Instant threat that was easy to explain to the public and media.
But in the post-information age that we also call the 21st Century, we have gotten more complacent and less willing to understand events in a larger contexts. Sure the the perpetrators of the attacks on 9/11 were dark-skinned (always a plus for the racist tendencies of the West) Muslims but who funded them (Saudi Arabia?) and what was their real motives? Too many people today are willing to just go down the road that Muslims want to kill Christians and that's why we have terrorists. No one seems to ask if the 21st Century terrorists aren't the same third party operatives as their 20th Century counterparts, just with different actors from central casting?
If we accept that there may be motivations beyond the obvious theological or political labels of a given terrorist, then we should become much more concerned about what is really going on. For instance, the average American thinks all Muslims are the same (not realizing how many different factions of Islam exist) and there is some kind of one over-arching organization that controls Islam (no more than there isn't one group that controls all of Judaism or for that matter, Christiantinty).
If no one council exists that holds equal sway over Shiites and Sunnis, then why do we paint all attacks in the 21st Century with the same brush? The attacks in France, London, Spain and Russia may all turn out to be conducted by "radicalized Muslims" but to what end? If in fact that are all working towards a common end, say total anarchy in Europe, who then is actually making the calls?