Ans.01. You are wrong, in every aspect. Korea and China are hardly Buddhists, presently not and in history has rarely become the major religion only for a few times before other religions took a dominant role. Korea and Burma for the most part of history were often never the aggressor with Korea being the opposite and constantly invaded throughout its history.
02. The difference between Islam and Buddhism is that Buddhism does not ever condone violence and segregation whilst Islam is the opposite.
03. Even if you could justify Muslims as being completely corrupt in their practice it does nullify the violent teachings present in the Quran with some sects emphasizing the violent quotes describing Muhammad's warlord ways which Buddhism completely lacks.
01. Buddhists constitute majority in both Korea and China. This is a fact and you show your own ignorance to deny it.
Korea as an independent country has a very recent history, most of the time it was under some other country.
03. No religion and no civilization can exist or survive, unless it has to take means to defend itself from its opponents.
So to say that Buddhism is against all violence is not true. Their monks may renounce the world and go to caves and hill tops, but the rulers have to defend their country and their people.
04. Islam on the other hand is a practical religion, war and defense and to maintain peace in the land is as important as praying in the mosques.
That is why Islamic teachings are for every sphere. War does not always means destruction and misery on land, it also means to remove corruption, mischief and injustice from the land.
You have a very wrong impression about Islamic Jihad and what are its aims.
04. Just look at teachings of Christianity….dont you wonder how come Christians became the people who shed maximum innocent blood?
The same is the case with Buddhism, when they became victorious, they show extreme cruelty, as we saw in Japanese of WW-2 time and what we see in recent massacre of Burmese Muslims by the Buddhists.