NO. Absolutely not. We can provide all the nuclear protection they need. They should concentrate on building up their conventional forces so they can be true allies and help share the burden of keeping their oil supplies flowing. I wouldn't object to 200,000 Japanese troops joning us in the ME. The mad mullah's are just as much a threat to them as they are to us.
No need. As others have posted already, Japan could become a strategic nuclear country within a *very* short time span. They have all the technological components, and know how, especially in the industrial machining equipment that would be required to shape the detonation assembly. They've had nuclear power plants for quite some time, and therefore should have a ready supply of nuclear material they can enrich to weapons grade. I'm sure that centrifuges wouldn't be a problem with their manufacturing capacity and prowess.
I do feel Japan needs to be re-militarized. I think the old ways are long gone, and, it's time that new Japan takes its rightful place in the world order. A second largest economy with almost no military presence ? That's a tad geopolitically untenable, to say the least.