In withdrawing the United States from the historic 2015 Paris Climate Agreement, President Donald J. Trump fulfilled one of his most prominent campaign pledges. But far from making America “great again,” the decision will endanger U.S. national security and prosperity by sabotaging U.S. global leadership and accelerating a planetary crisis from which not even an isolationist America can escape. Trump’s myopic and backward-looking decision ignores a reality of contemporary global life: The United States cannot advance its national interests or protect itself from transnational threats by pretending to be an island or by building walls, in the vain hope of insulating itself from dangers that refuse to respect borders.
It is hard to overstate the magnitude of the president’s step, taken despite urgent entreaties from America’s closest allies and U.S. business leaders. By withdrawing the United States, Trump is taking a wrecking ball to the most important multilateral agreement of the twenty-first century. After two decades of fruitless negotiations on a successor to the Kyoto Protocol, 195 countries in Paris in December 2015 finally pledged to major reductions in greenhouse gas emissions. At the insistence of the Obama administration, the climate accord was crafted not as a binding treaty—which could have run afoul of domestic U.S. sovereignty concerns—but as a voluntary agreement. Under this so-called “pledge and review” arrangement, each country declared its own “intended nationally determined contribution” (INDC) to reducing greenhouse gas emissions. This allowed the parties to tailor their commitments to their unique national circumstances, rather than adopting a one-size fits all formula.