The United States is globally isolated following Syria's embrace of the Paris Climate Treaty. Syria was the last country, other than the United States, not to join the treaty.
Paula Caballero, Global Director of the Climate Program at Washington DC-based think tank the World Resources Institute said that “with Syria on board, now the entire world is resolutely committed to advancing climate action – all save one country. This should make the Trump administration pause and reflect on their ill-advised announcement about withdrawing.” It remains to be seen whether or not this will impact the actions of the US delegation over the next fortnight of talks at COP23. The White House has said it “will promote coal, natural gas and nuclear energy as an answer to climate change.”
Trump's war against the environment is part of a broader effort to tear down his predecessor's legacy.
Domestically, the Paris withdrawal appears to be part of a larger scheme to roll back Obama-era environmental regulations, including the Clean Power Plan which was supposed to be one of the main vehicles for the US to meet Paris targets.