I'm having a lot of trouble understanding what you are trying to say. Are you suggesting that if the explosions didn't take place that everything would be fine at Fukushima? The reactors would still be overheating, explosion or not explosion. Thus, Japan would still have a nuclear crisis. "International"? In what way is this an international nuclear crisis? I could see the argument that this is an international economic crisis because of the lost output of Japan for companies abroad and the contaminated food not being sold to international markets etc, but the nuclear effects are limited to around 30 - 40 km outside the plant (I live about 200 km southwest of the plant and if it weren't for the news I would never know that anything was wrong). Yes I am aware that they found minute amounts in 15 states of America, but until they are enough to cause any kind of effect at all, I don't think this can be considered a catastrophe for any country besides Japan.
There was not a steady stream of hydrogen coming out of the reactor, so by your own example when the stream from the reactor stopped being vented, wouldn't the flame have been sucked back in like the can with the hose disconnected? Yes, the hydrogen came from the overheated zirconium oxidizing, and it was vented along with the steam inside the reactor (unknowingly at first) into the reactor building to relieve reactor pressure. It then subsequently was ignited by something unknown (to me at least). You say air must have been "pulled in"? It sounds like you think the explosion happened inside the reactor, which it didn't. There is already air in the reactor building. If I am misunderstanding what you said, then I apologize.