russian annexation of crimea

Russia simply walked over to part of ukraine's territory( in crimea) and simply annexed crimea to be part of russia. Why? Because that region have a sizeable population of russians in the region. what will happen britain claims USA just because we speak english. what happened to diplomatic solutions? Now this action by Russia and putin will shape different conflicts that happening around the world. Now China can say some parts of japan and other parts of southeast asia will be part of china, because it was historically was so. North korea can go and attack south korea and try to annex  the country. America and the western allies simply failed to stop PUTIN away from the shores of ukraine, now it gives other country to think that we are weak and can't do anything.