Amid the confusion and the almost deafening cries of treachery and collusion over Donald Trump’s relations with Russia, few noticed the most tangible outcome of this week’s Helsinki summit. In the lead-up to his face-to-face talk with Vladimir Putin, senior US and Russian diplomats — in close coordination with leaders from mutual ally Israel — brokered a deal among all the warring parties (bar the Islamist terrorists) finally to end the devastating seven-year Syrian civil war.