The North Atlantic Treaty Organization leaders will attempt to make a convincing show of unity today when they meet to conclude a summit already overshadowed by bitter rows about the future of the alliance.<br />'' <br />''Last year, the Western allies' get-together was derailed by United States President Donald Trump's demand for greater European defence spending, but 2019's provocateur was France's President Emmanuel Macron.<br />'' <br />''The French President has called for a renewed strategic dialogue with Moscow and demanded that Turkey explain itself over its assault – backed by Syrian rebels Paris sees as extremists – on Kurdish forces and its purchase of the Russian S-400 air defence system.<br />'' <br />''The leaders met in various groups in London yesterday before having dinner with Queen Elizabeth-II in Buckingham Palace, but Mr Macron refused to withdraw his charge that NATO strategy is brain dead and Mr Trump continued to insist some capitals were delinquent in paying their way.<br />''<br />''<span style="color: #222222;">The row set up a tense last day of what NATO Secretary General Jens Stoltenberg had hoped would be a 70th anniversary show of unity for the most successful military alliance in history and a demonstration that the West can stand up to challenges from Russia and China.</span><br />