UNITED NATIONS, United States, Sept 20, (AFP) – British Prime Minister Theresa May urged world leaders to defend the rules-based international order and its multilateral institutions Wednesday, one day after US President Donald Trump had hailed national sovereignty. Addressing the UN General Assembly, May cited many dangerous challenges facing member states — from Syria’s use of chemical weapons on its own people to terrorism to economic equality — and called for unity of effort. “I believe that the only way for us to respond to this vast array of challenges is to come together and defend the international order that we have worked so hard to create and the values by which we stand,” she said. “For it is the fundamental values that we share — the values of fairness, justice and human rights — that have created the common cause between nations to act together in our shared interest and form the multilateral system.” “And it is this rules-based system that we have developed … which enables the global cooperation by which we can protect those values,” she said. May’s comments marked a striking contrast to Tuesday’s speech by Trump, in which he used variations on the word “sovereign” or “sovereignty” more than 20 times and argued that: “The nation-state remains the best vehicle for elevating the human condition.” Trump’s nationalist bent is a break from decades of US support for multilateral efforts, and has led him to dump a planned trans-Pacific trade pact and threaten to pull out of the Paris climate accord and Iran nuclear deal. May, by contrast, cited both free trade agreements and the Paris accord as examples of a rules-based international system that ensures peace and prosperity. After her speech, however, May was to fly back to London to chair a cabinet meeting on pulling her nation out of arguably its most significant multilateral arrangement — the European Union.