Caucasian oil politics are FUBAR, especially in Georgia where warlords control entire states that key pipelines flow through, tapping them at will to fund their agendas with the government/military unable to intervene due to general incompetence or lack of firepower. The natural gas/oil infrastructure built in the USSR crosses boundaries that have been artificial for decades, if not centuries, with ethnic minority communities spanning the borders of what are now countries (see: North and South Ossetia situation.) Governments being pro-Western or pro-Russia leaves them hosed either way when trying to appeal to militant groups who identify with a global struggle for free Islamic republics, and the US seems content to sit back and smugly criticize how Russia handles its Caucasian situation while taking field notes on how to do the same things in Afghanistan/Irag (leveling entire towns, bombing campaigns that would bring a tear to Stalin's eye, etc, etc.)
Airport has alot of foreigners.
For all "enemies" of the Russia, it usually goes like this: Russia has violent buttsex with victim at home while rest of the world acts like it doesn't notice anything while shaking Russian hands over gas and oil deals. So "help us, world" doesn't really work and nobody can hear you scream in space / RUSSIA
So theoretically, international attention is very much in the interest of the enemy and if you want to kill a bunch of foreigners but still point at russia as the part of the problem, you'd probably go to a russian airport, right?
Makes sense to me...
And even if it's EVIL CONSPIRACY, blowing up bunch of japanese tourists has 2 perfect benefits -- first, you're less of a traitor to your homeland due killing less russkies, and second -- russian people have resigned to Kremlin anyway so Putin can have as many wars with "terrorists" as he wants and doesn't need his own 9/11 to make people unite. It's - again - the international world police that needs reassuring that raping of minor country is needed and "they started it"...
Gunslinger