join battle (with someone or something)

To engage in a fight, argument, or competition with someone or something. Teams from all across the state are coming together to join battle this weekend at the events center. Oh, I've joined battle with the principal about my choice of curriculum many times before—I'm not worried.

If you join battle with someone, you decide that you will try to defeat them in an argument or contest. Carter led the challenge against the Prime Minister and now finds himself joining battle with two of the party's most admired figures. European finance ministers will join battle this weekend in a new row over who should represent the Euro on the international stage.