http://www.straitstimes.com/opinion/will-japans-victorious-ldp-revise-the-constitution
Article 9 on the Japanese constitution is considered to be deterrence against war.
But, I think that whether Japan is involved in war or not is subject to interpretation of the Article 9. And, the interpretation is also dependent on diplomatic environment.
We must remember that what we should preserve is not rule but real peace.