Poland's President Andrzej Duda and first lady Agata Kornhauser-Duda arrive for a reception for NATO leaders at 10 Downing Street in London, Tuesday, Dec. 3, 2019. U.S. President Donald Trump and his NATO counterparts were gathered in London Tuesday to mark the alliance's 70th birthday amid deep tensions as spats between leaders expose a lack of unity that risks undermining military organization's credibility. (AP Photo/Frank Augstein)