BRUSSELS (AP) — European allies at NATO on Thursday brushed aside concerns that the United States has stepped back from its leadership role of the world’s biggest security organization , leaving them and Canada to do the lion's share of defending Europe. U.S. Defense Secretary Pete Hegseth did not attend Thursday’s gathering of defense ministers at NATO headquarters in Brussels. His no-show came after Secretary of State Marco Rubio skipped the last meeting of NATO foreign ministers in December.