When Japanese say that a country's people can fight, it is because Japan has battled them. And, it is talked about openly in different nations with different perspectives.
When people of other nations say that another particular country's people can fight, it may only be because they have heard a story of a battle. Though those battles may also be private and secret because they violate treaties in peaceful times. It is not on a world platform for others to discuss.
Yet many people scrutinize only Japan.