It has border disputes, but it hasn't been involved in any major military conflict since 1979.
Most (probably all) countries in South and East Asia have multiple border disputes. Japan has disputes with China, Russia and South Korea. India has disputes with Pakistan, China and Nepal, and used to have disputes with Bhutan, Sri Lanka and Bangladesh. See a trend? Every major country in the region has or has had disputes with every neighboring country.
Most (probably all) countries in South and East Asia have multiple border disputes. Japan has disputes with China, Russia and South Korea. India has disputes with Pakistan, China and Nepal, and used to have disputes with Bhutan, Sri Lanka and Bangladesh. See a trend? Every major country in the region has or has had disputes with every neighboring country.