That muted tone contrasted sharply with European leaders' swift condemnations and with statements from his own envoy to NATO. Ambassador to NATO Matthew Whitaker pledged the defense of "every inch of NATO territory," echoing the language of the alliance's mutual defense clause. Washington's silence has been almost deafening," an Eastern European diplomat said. In Brussels, NATO Secretary-General Mark Rutte announced Operation Eastern Sentry to reinforce the alliance's eastern flank, deploying additional troops and air defenses. Analysts say the incident highlights the president's push for Europe to bear more responsibility for its own security.