MANAMA, Bahrain — Eyeing a future Middle East in which the Israeli-Palestinian conflict is a thing of the past, business executives, billionaire investors and Middle East diplomats gathered in Bahrain on Tuesday for a White House-led conference meant to promote a long-delayed peace plan by trumpeting the economic opportunities it could spawn.

“One who is more hopeful, and sees opportunity for his or her family, will put energy into pursuing opportunity, instead of blaming others for their current misfortune,” said Jared Kushner, President Trump’s son-in-law and leader of the administration’s Middle East peace initiative.

The brainchild of Mr. Kushner and his team, the two-day “Peace to Prosperity Workshop” brought Arab dignitaries in dishdashas and headdresses together with skullcap-wearing Orthodox Jews from Israel and the United States.

It began on a somewhat shaky footing, after the White House’s glossy economic proposal for the Palestinians, published on Saturday, drew a largely negative response. Critics dismissed it as a rehash of ideas put forward in earlier efforts to resolve the conflict, took umbrage at photographs of Palestinians who benefited from American aid programs that the Trump administration has since cut, and assailed its omissions.