Leaders will gather in the Turkish capital this week for a high-stakes NATO summit amid transatlantic tensions and growing uncertainty. Hosted by Turkish President Recep Tayyip Erdogan, the July 7-8 meeting will bring together leaders from NATO’s 32 member states in Ankara.

A major challenge for the alliance is how to turn money into new military capabilities in a short timeframe.

US President Donald Trump heads to the NATO summit in Ankara amid escalating tensions and sharp criticism of European allies over defense spending and Iran.