Since the establishment of the various military branches, the competition between them has never ceased. The Army wants more soldiers and tanks; the Navy desires more warships; the Air Force craves more airplanes...
Everyone hopes to be the decisive force on the battlefield, the pillar that supports the nation's fate.
As for national defense, countries tend to prioritize their military developments based on geography, among other factors. Island nations prioritize their navies, while continental countries maintain a tradition of ground forces.
Speaking of the Navy, as long as a country has its own coastline, the navy is undoubtedly a branch that should be developed. It's evident that even nations without coastlines maintain navies.
Moreover, nations around the world now trade with the Great Tang Empire to some extent, making the sea routes of the Endless Sea busier than in the past 10,000 years combined.
