Your only "quick" options (wait ... Have you obtained. Zaldox'ian thaleron radiation disrupter cannon? If so, then this question is moot, use that fucker-- it only has three shots and you'll need to take out Kyoto, Osaka and Tokyo-- that's about 70 million and should do the trick, otherwise....) you'll need a stockpile of WMDs. Nukes, bio weapons and/or chemical weapons.

Problem is, you use those and the US will launch nukes at you. So, unless you have a Rekalian quantum inhibitor (should destabilize the fissile material in a standard nuke), you're SOL. There is LITERALLY no possible way to quickly take out Japan in an blitzkrieggy invasion. None. Zero. Don't sit here demanding that I invent something. Not even Guderian x Rommel ^ Von Manstein could invent such a scenio without the Zaldox'xian disrupter and Rekalian inhibitor.

Fighting the US means fighting these nations (all have mutual defense pacts with the US):

  • Japan
  • Philippines
  • Australia
  • New Zealand
  • Canada
  • The U.K.
  • Norway
  • The Netherlands
  • France
  • Spain
  • Portugal
  • Italy
  • Greece
  • Turkey
  • Germany
  • Belgium
  • Luxembourg
  • Poland
  • Denmark

And for good measure, more than likely (due to their overwhelming dependence on the US):
  • Saudi Arabia
  • Kuwait
  • Israel
  • Egypt
  • Mexico
  • UAE

Have fun taking them all out while you're at it.

Browse photography at Denver.Gallery.