Ha, ha! Pack it full of cornspiracy theories, North Korean mini-subs and nukier weapons. Yeah, that's the ticket!
FWIW, the casing in the well was cracked - read that iffy - they were trying to fix it and the well "blew out". Think about how in the movies when the oil well comes in and starts shooting out the drill string, oil gushing high into the air like a black fountain. In this case, there was a large release of gas. Unrefined natural gas contains many volatiles (butanes, propane, methane, etc) and can burn REALLY HOT. To get an idea of what was belched out and up to the rig on the surface, convert those images of billowing oil clouds at the wellhead into gas bubbles. At a mile down, the pressure keeps the bubbles the size you see on TV, but, as it rises and the pressure falls, the bubbles grow continually bigger - maybe ten times in volume. At the surface, it must have been like being inside a propane tank. Eventually, the gas found an ignition source. That's why the fireboats couldn't put it out. Had that been on land, Red Adaire, Jr. would have dynamited it to starve the fire out. But it was a mile down.
The government has nothing to gain in sabotaging a deep ocean well. C'mon, guys, that oil comes straight to the good old USA and the Texas refineries. Money for everyone, all the way around. And sealing the well with a tactical nuke, well, it would have to be something like a depth charge designed to operate that deep. A regular warhead might not be able to take the pressure and just crap out without detonating. Now, once you do achieve a detonation, you have that nice mushroom cloud and fallout to deal with. Not so friendly to our Caribbean neighbors, much less Floridians. (Aren't they one and the same?) Anyone up for skimming up radioactive oil slicks? And, please, believe me when I tell you, there are NO SMALL NUKES.
The problem that BP is having, as well as the whole oil exploration/productoin industry, is they are trying to apply surface fixes to a problem five thousand feet down. You would think that, after thirty years of reaping the economic benefits of deep water drilling, the industry would have put as little as one percent of the money into custom-tailored machines and tools/techniques for dealing with this kind of scenario. After all, there have been numerous well failures topside, so why did they think working under hundreds of tons per square inch would be any different? "If I don't think about it, it ain't there."
Now, all of you conspiracy theorists, Libertarians and, especially, MODERATORS, please put this HIGHLY POLITICAL discussion over on the R&P where it should rightly reside.