Clean energy and climate will top the menu but political calendars will constrain ambitions when freshman Prime Minister Justin Trudeau receives lame duck U.S. President Barack Obama and Mexican President Enrique Peña Nieto, who is in the last third of his six-year term, in Ottawa at the end of June, resuming the practice of so-called ‘Three Amigos’ summits among the North American leaders.

Diplomatic observers predicted that deepening trilateral cooperation on clean energy and energy integration will dominate the leaders’ agenda, but that bold new initiatives are unlikely, since none of the three NAFTA-zone leaders has surplus political capital to burn.

Mexico’s Peña Nieto has championed unpopular reforms to his country’s previously closed and state-operated energy sector that were designed to invite outside investment in both fossil and renewable developments; but he is in the twilight of his term and bruised by allegations of corruption. Obama is maneuvering to protect as much as possible of his administration’s climate policy legacy from attack should Donald Trump succeed him in office in nine months.

For his part, Trudeau already faces a heavy do-list of as-yet unfilled campaign promises. Pending decisions on the proposed Trans Mountain and Energy East pipelines, each strongly opposed in key electoral regions, are among the most politically explosive items on that list.

The summit comes a year later than planned because of tensions between former Conservative Prime Minister Stephen Harper and the other two ‘amigos’ over Obama’s refusal to approve the Keystone pipeline, which Harper backed, and Canada’s imposition of a detested visa requirement on Mexican visitors. (Mexico places no equivalent requirement on Canadians traveling to that country.) “The new Liberal government has not said publicly that the visa issue will be resolved in time for the summit,” the Canadian Press writes, “but Trudeau has said he wants to see it done away with.”

For all three leaders, modest wins requiring little political capital and carrying limited downside risks are likely to be the order of the day, observed Kevin Thompson, executive director for North America policy and relations at Global Affairs Canada. “This is not really the time for grand visions.”