former secretary of state dean acheson<u+2019>s memoir, <u+201c>present at the creation,<u+201d> is a classic account of how a durable and productive atlantic alliance, based on common values and a cleareyed judgment of america<u+2019>s strategic interests, rebuilt europe after world war ii and produced international institutions responsible for the security and expanding economic opportunities that have been of such benefit to the united states. today we are faced with this question: will two remarkable events within the past several months, the brexit vote in britain and the election of donald j. trump as president, threaten to undo what harry s. truman, george c. marshall, acheson, dwight d. eisenhower and their farsighted counterparts in europe and asia created 70 years ago? acheson<u+2019>s book recounts the struggles, the intense negotiations and the occasionally brilliant statecraft that established the north atlantic treaty organization . the foundations of nato became the european union and other international institutions. they also led to the bretton woods agreement stabilizing currencies; the marshall plan, which saved much of europe from tyranny; efforts to devise an international understanding on nuclear weapons; and development of the truman doctrine, which halted communist expansion in europe. these eventually led to border arrangements that produced freer flows of people and goods, a common currency in much of europe and, most of all, a stable and secure trans-atlantic region. these institutions, while not perfect and always ripe for reform and evolution to meet contemporary challenges, have brought prosperity to millions and created a remarkably peaceful period in a european history filled with costly wars. all this and more represented the foundation of an international order not just in europe but also asia that would last, with several detours, until 2016. as the brexit vote and mr. trump<u+2019>s election showed, too many of our fellow citizens feel left out of this history. but, if he is to be taken at his word, mr. trump now proposes that these international arrangements be called into question, so far without much of a plan beyond retreating to <u+201c>fortress america.<u+201d> on some issues, he has a point: those nato allies that have not met their promises to contribute more should help pay for the common defense. but calling into question the solemn guarantee to defend a nato ally that is attacked can lead only to a test of wills with russia. mr. trump also proposes to withdraw from the north american free trade agreement, enacted in 1994 with bipartisan congressional support. explicitly or implicitly, he offers encouragement to right-wing leaders and parties in several european nations, virtually all of whom share nationalistic and xenophobic beliefs and who wish to erect barriers to immigration similar to mr. trump<u+2019>s wall for the border with mexico. or take mr. trump<u+2019>s vow to withdraw from the 2015 paris climate agreement, produced after many months of intense multilateral negotiations, and to cancel the climate action plan created by the obama administration. virtually the entire world has signed the paris accord. unilateral abrogation would be a huge blow to the united states<u+2019> international credibility, and make it impossible for the world to meet the carbon emissions goals necessary to stall global warming . addressing climate change is not just about <u+201c>soft power.<u+201d> senior military commanders believe that global warming threatens to become a major security problem, with mass migrations from coastal cities and major disruptions in agricultural production. the united states is engaged in a global debate about who will set standards for the future on crucial questions like international governance, human rights, the protection of free market principles and the resolution of problems without resort to force. this matters to americans, and particularly to the americans who voted for mr. trump and will still have to compete in the global marketplace for jobs, despite the wish that the country go it alone. truman, marshall, acheson and eisenhower, through their belief in having the strongest military in the world to back a focused and creative diplomacy, put america in a position to lead the world for 70 years. will mr. trump cede that responsibility to moscow, beijing or tehran? the anchor of american military presence in europe and asia, including bases and fleets, contributes mightily to stability in both regions. there is no benefit to america in a world where individual nations develop their own security arrangements, including, quite probably, nuclear arsenals. north korea should be example enough. the surprise, if not shock, of mr. trump<u+2019>s victory lingers. predictably, much of the focus is on the domestic changes his election may bring. but serious foreign policy experts and institutions must process the implications of his victory and the brexit vote and place them within the lessons of the post-world war ii world. wise leaders such as truman, eisenhower, marshall and acheson constructed a temple in which freedom could thrive and economies could prosper. the interior of the temple may be in need of renovation, but mr. trump should not pull apart its central pillars and bring it crashing down. william s. cohen is a former republican senator and secretary of defense. gary hart, a former democratic senator, is chairman of the international security advisory board, which advises the state department. follow the new york times opinion section on facebook and twitter (@nytopinion), and sign up for the opinion today newsletter . a version of this op-ed appears in print on november 22, 2016, on page a31 of the new york edition with the headline: don<u+2019>t retreat into fortress america. today's paper | subscribe
don<u+2019>t retreat into fortress america
william s. cohen gary hart