a country invades or attacks your country with weapons, like bombs, missiles, men.
or if they declare war against you and come to your country with violence and so on.
i absolutely agree with you,
by the way, the idea of your comments reminds me of an anecdote- wanna share it with you;
" An English man stares madly at a Turkish man from opposite side , it goes on for a while... Turkish man gets irritated and asks him - "what is your problem with me? "
English answers -"your grand , grand father killed my grand , grand father in Gallipoli(west of Turkey) Battle, so i hate you!!!"
Turkish answers -" then, WHAT WAS HE DOING IN MY COUNTRY?"