...I think the tributes are more like paying respect and acknowledgment of the supremacy of the Chinese kingdom and not to suppress the natives.
Yeah...It is called 'extortion'. You pay me so I do not beat you up.
The conquest and maintenance of lands outside one's borders are not easy. Defeating that army is one thing, but continued suppression of resentment, pacification, mollification, deals making, trade, etc, are different, as the US found out in our recent military adventures. This is even more problematic if bodies of water are involved. Conquests of
BORDERING lands are actually easier than conquests of lands protected by bodies of water. The serious study of the technical aspects of military affairs are scant when it comes to the Chinese and their supporters in this forum.
Man -- as a species -- evolved to be land based. Ninety nine percent of what we invented and do are for land based activities. So when we encounter a body of water, naturally we hesitate. We have to invent new ways to survive in the water. As an interesting aside, in special operations training, the first and best test to eliminate candidates is water survival. For the US military, there are very few blacks in the special operations community, specifically the SEAL teams. Most American blacks are urbanites or city dwellers so they do not have much experience with water outside the community swimming pool.
Take everything that make up a special operations soldier, then scale those factors up to the national level.
Overseas expeditions are enormous undertakings, especially when when the word is literal and not figurative -- involve an ocean or a sea. To commit to a conquest of a land that is geographically protected by water means the military must first be mobile in doctrines, willing to be expendable, willing to be stationed for extended duration away from home, willing to live natively as in 'off the land' if necessary, innovative, and independent while away but submissive to orders from home when summoned. The people inside this military must also be extraordinary, not in the sense that individuals are geniuses but in the sense that they are disciplined, trained higher than the standards exhibited by other militaries, better equipped, and philosophically and morally motivated towards what they do. In other words, an expeditionary military is the best type of military that can be created.
In military history, this type of military is actually rare and even rarer are the ones that can cross water and achieve its goals. The Romans and the Brits are examples of this extraordinary type of military. Today we have the US military. China is a majority land power, not a maritime power. The Chinese navies in history have been used mainly to support land based objectives on home soil, not in overseas ventures. The history of the expansion of the various Chinese empires have been land based.
So if China in history have not taken overseas territories is because that historical China was not able to do so. For those island countries that were extorted, they paid because it is less expensive than to be repeatedly fighting off Chinese invaders. They probably did not believed that the Chinese military was not capable of sustaining an overseas territory. Often, an implied threat is just as good as an explicit one. So they paid the extortion. There is
NEVER any respect by the victim when being extorted, unless the interpretation is 'fear' and not 'respect' in the true sense of respect.