NATO is a military alliance established by the North Atlantic Treaty of 1949. The alliance constitutes a system of collective security whereby its independent member states agree to mutual defense in response to an attack by any external party. Recent tensions between Zelensky and Trump are cause for concern. - NATO Secretary-General Mark Rutte advised Volodymyr Zelensky to restore his relationship with Donald Trump. - The urging follows a tense and unproductive meeting between Zelensky and Trump at the White House. - The meeting was intended to finalize a minerals agreement but escalated into a heated confrontation. - Trump and his Deputy JD Vance criticized Zelensky for not being grateful enough for US support during the live television event. - Rutte emphasized the importance of the US and Ukraine maintaining a strong relationship for European security.