Influential former world leaders now working to promote peace, justice, and human rights warned that their mission and the joint goals of people around the world have been seriously impeded by a shift away from multilateralism in recent years, especially since President Donald Trump took office.

The Elders, the coalition founded by former South African President Nelson Mandela, suggested in a statement on Tuesday that the United States' withdrawal from numerous international accords and institutions is sabotaging efforts to combat the climate crisis, human rights violations, nuclear proliferation, and other dangerous forces.

"Without a concerted commitment to defend multilateralism, we will not bequeath a safe world to future generations," said the Elders, who include former Irish President Mary Robinson, former U.N. Secretary-General Ban-Ki Moon, and former Liberian President Ellen Johnson Sirleaf. "They will neither forget nor forgive such a collective failure."

The multilateral system is under unprecedented attack. Leading powers, including the US, are threatening to undermine critical efforts to tackle global challenges, from the #climatecrisis to nuclear #nonproliferation. The Elders' Statement: https://t.co/tvKpE03pWZ #NextGenTrade — The Elders (@TheElders) December 3, 2019

The statement comes as world leaders attend the United Nations Framework Convention on Climate Change (COP 25) in Madrid, the annual climate summit which this year counts no senior White House officials among its attendees, following President Donald Trump's steps last month to begin formally leaving the Paris climate agreement.

Trump's "myopic and self-harming" withdrawal has left other governments, the Elders said in their statement, with no choice but to redouble their efforts to limit climate-warming fossil fuel emissions:

All other signatories must now use the upcoming COP 25 summit in Madrid to urgently step up their climate action and ambition. Countries must cut carbon emissions more drastically and quickly than in previously-submitted pledges, and also adopt rigorous monitoring of compliance with such commitments.

In addition to leaving the Paris accord, Trump has directed the U.S. to withdraw from the U.N. Human Rights Council, citing alleged anti-Israel bias; the Iran nuclear deal and the Intermediate-Range Nuclear Forces (INF) Treaty to prevent the proliferation and use of nuclear weapons; and is blocking the appointment of judges at the World Trade Organization (WTO).

"Getting others to cooperate by means of internationally-agreed mechanisms is less costly and more reliable than unilateral force."

—The EldersThe president has also not confirmed that the U.S. will accept Russian President Vladimir Putin's offer to extend the New START Treaty, which would limit signatories to no more than 1,550 deployed nuclear warheads and 700 deployed missiles and bombers and which has been called a "security no-brainer" by peace campaigners.

The president has frequently claimed multilateral agreements are "bad deals" for the U.S., but the Elders argued that multilateralism works in all nations' interests.

"Getting others to cooperate by means of internationally-agreed mechanisms is less costly and more reliable than unilateral force," the Elders wrote.

The Paris climate agreements and the collection of global accords and institutions forged after World War II are "far from perfect," the Elders acknowledged.

But this network of cooperative agreements "has nevertheless decisively supported the pursuit of peace, security and the protection of human rights, as well as economic and social progress across the globe, for over seven decades."

The Elders called on WTO member states to take the immediate step of appointing judges with a majority vote despite U.S. efforts to block the judges' confirmation, "to avoid the collapse of the WTO's entire dispute settlement capability."