The housing crisis was simply the match that lit the powder keg that is the recession that we are in today.
The housing crisis was caused by two major things.
-1. The federal reserve kept interest rates too low for too long, giving a massive amount of practically free credit to the major banks.
-2. The banks created credit default swaps for the subprime mortgages and other sectors of their risk. They considered this the holy grail of banking, they could make as many loans as they want to whoever would take the money, then they could package the risk on those subprime loans into a bundle, and sell the bundle to other banks around the world.
You're absolutely right about it being a world wide bubble, everyone and their moms were trading credit default swaps, and very few people knew what they actually were.
Along came one day when a large number of the subprime lendees declared bankruptcy, sending shockwaves through the banking system. This first bank to go was Bear Sterns, which got a bailout and was sold to JP Morgan, the second was Lehman Bros, who didn't get a bailout, and bit the dust. One after another, the banks begin to collapse when their artificially created bubble popped, and we, the tax payers were left without a chair when the music stopped.
So in short, it was the Fed's AND the bank's fault, and it wasn't an isolated american incident. It was international, like you suggested, we all bear the blame.