Let's not forget it's convenient for conservative parties of BOTH sides to have some red meat to throw to their country's nationalists. Normal, everyday people scarcely have the time or interaction to have strong feelings about another country whose people they don't encounter that often, independent of history. But when you stir up your constituents to unite against an out-group, you can get them out to the polls and have a nice convenient threat to accuse the other guys of being soft against. They will become real friends when the real threat from China is greater than the political benefit of using each other to keep a united nationalist wing.