As Japan, never declare the war against any country with no provinces in Japan region until 1821, while having 100 heavy ships or more.
(It's okay to colonize empty provinces, diplomatic annexation, or letting colonial nations declaring war.
Also, okay to be declared war and engage defensive war. But should not take any provinces outside Japan region through the war)
Inspired by, of course, 日本国憲法9条 (Article 9 of Japanese constitution)
Also inspired by 日本国自衛隊 (Japanese Self-Defense force), the de facto military force of post-ww2 Japan, which nowadays has less army and huge amount of navy.
- That dude in the High Castle
As Japan, own (or have your non-tributary subject own) Hawaii, and 40 provinces in North America super region, including Los angeles, San fransisco, Seattle, and Anchorage.
Yup, you know 'The man in the High Castle'.