NATO leaders gather in Ankara to tackle US-Europe tensions, defence gaps and support for Ukraine’s military resilience.The war in Ukraine and the fall out from the Iran conflict are high on the NATO summit’s agenda this week. But well before Secretary General Mark Rutte takes to the stage on Tuesday, NATO’s most powerful individual had already set the tone.“Ridiculous for the U.S.A. to continue along this one sided path when the relationship is not reciprocal,” US President Donald Trump wrote late last week. “They were not there for us!!!”Recommended Stories list of 3 itemsend of listAs 32 leaders of the transatlantic body gather in Ankara for their two-day summit starting on Tuesday, the frosty relationship between the military alliance’s members and the United States has emerged as the single biggest challenge overshadowing its future.NATO says the summit will focus on three priorities: increasing defence investment, expanding Europe’s defence industrial base and ensuring long-term military support for Ukraine. The meeting comes after allies pledged last year to spend the equivalent of five percent of GDP on defence, with European allies and Canada increasing defence investment by $139bn in nominal terms in 2025 alone.But talks will be overshadowed by Trump’s threats to pull the US out of NATO and his plan to move troops and weapons out of Europe. On May 1 , the Pentagon announced the withdrawal of about 5,000 troops from Germany, …