Buddhist kingdoms have entered war before.
Ming-Kotte WarAs to who started what, I've forgotten about it.
Last time when I watched voyages of Zheng He on National Geographic, I think it started from a civil war for the possession of a Buddha relic.
Busy with the civil war, they didn't wanna pay tribute to China or something which got them destroyed by Zheng He
Depends on the schools of teaching, the monks may be required to take a vow of not eating meat.
In ancient times, even Buddha ate meat. In fact, Buddha died from consuming tainted pork
Buddhist monks generally live on alms. People offer food to them and they were not allowed to choose their food and only consume what was offered (mostly leftovers).
Buddha allowed meat for his disciples under a condition, that is that his disciples did not know, or even suspect that the meat offered to the monk was done so by killing the animal solely for the purpose of offering them to the monks. It's kind of like in restaurants now where fishes are kept alive in aquariums and when you order that fish, they purposely kill the fish for you.
This is the difference between taking a life and eating meat.
However, there are Buddhist schools who are now arguing that the act of eating meat itself is creating more demands for meat, thus encouraging the killing of animals. You will see that some of the Thai monks, or even Nepalese monks eat meat. In general they eat what is offered.
the whole not eating meat thing is the bigger picture: that is to replenish the stocks of meat that you have ate, they would need to kill more. Also depends on the level of your Buddhist practice: if you want to save all beings would it be logical to eat their flesh while you're at it? Its like a doctor that works as a murderer at night.