France, June 15 -- Leaders of some of the world's biggest economic powers arrived in the Canadian Rockies on 15 June for a Group of Sevensummit, overshadowed byan escalating conflict between Israel and Iranand U.S. President Donald Trump's unresolved trade war with allies and rivals alike.

Israel's strikes on Iran and Tehran's retaliation, which appeared to catch many world leaders off guard, are the latest sign of a more volatile world as Trump seeks to withdraw the US from its traditional role as global policeman.

Speaking on a flight to Canada for the summit, British Prime Minister Keir Starmer said he had discussed efforts to de-escalate the crisis with Trump, Israeli Prime Minister Benjamin Netanyahu, and other world leaders.

Brit...