Taken from www.dannychoo.com:
After Japan lost the last war, they signed a treaty that stated that Japan was not allowed to form an army of humans. But there was nothing in the treaty mentioning that Japan wasn't allowed to form an army of Gundams...
The Japanese Ministry of Defense is holding a Defense Technology Symposium where part of the program covers "Towards the realization of Gundam" - the program is available in PDF format on the Department of Ground Systems Development page.
Below is a snap of the PDF file showing "Towards The Realization Of Gundam (Advanced Personal Equipment Systems)" which kinda stipulates some sort of walker suit but you never know...
Japan's Ministry of Defense website:
http://www.mod.go.jp/
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So Japan's MoD decided to "create" a gundam. For what purpose we don't know :p