There is no excuse or justification for terrorism. But that doesn’t mean it is inexplicable, the product of purely irrational evil impulses. There will always be people willing, under certain circumstances, to resort to terrorism. If we want to fight terrorism effectively, we have to avoid creating those circumstances.
Successive Russian governments created the conditions in Chechnya that allow terrorists like those responsible for the Beslan atrocity to flourish. There was a long history of oppression, from Czarist times to mass deportation under Stalin. But the current outbreak can be traced most directly to the actions of Yeltsin and Putin. When Chechnya sought independence from Russia after the breakup of the Soviet Union, Yeltsin’s response was one of brutal and incompetent repression, eventually leading to an effective Russian withdrawal, and the creation of a failed state, in which warlords and militias flourished, and terrorism established itself.
After a series of Chechen terrorist attacks in Moscow and an attempted invasion of the neighbouring republic of Dagestan, Putin came to power with a policy of crushing Chechen resistance, which he implemented with high civilian casualties and the destruction of much of the capital city of Grozny.
Again, this history doesn’t justify, excuse or mitigate horrible crimes like the one we have just witnessed. But there is also no excuse for those who advocate policies that are bound to promote terrorism while rejecting any analysis of “root causes”.
fn1. Those interested in a more detailed history can find what seems to be a pretty good one at Global Issues. This is a leftwing site, but seems to give fairly objective coverage.