The United States has a pretty good track record at winning wars, but there is only one important conflict in recent memory where we also won the peace. Fortunately, this singular victory occurred in conjunction with the largest of them all, World War II.

The postwar peace was the result of an extraordinary work of American statecraft. It occurred because a very serious and smart group of men realized that, if the fruits of the hard-won victory were not to turn rotten again, the flaws in the world system that had led to the global conflagration needed to be corrected. So they created two critical institutions. The first was the Western alliance, later formalized as the North Atlantic Treaty Organization (NATO), to provide for collective security of the democratic world, and thereby decisively deter any future totalitarian aggression. The second was a system of international free trade, formalized as the General Agreement on Tariffs and Trade (GATT, later renamed the World Trade Organization), to enable global economic recovery and prosperity, thereby ensuring the continued stability and growing strength of the democracies themselves.

These two pillars of the postwar order -- NATO and GATT -- lay the foundation of a world so much more peaceful and prosperous than the prior chaos that one its leading architects, Truman administration secretary of state Dean Acheson, titled his memoir Present at the Creation.

The creators of the postwar order built on the basis of hard-won knowledge. Free trade is necessary for economic prosperity for the same reason that long distance transport is. Everyone understands that advances like the Erie Canal and the transcontinental railroad greatly accelerated American economic development by cheapening internal transportation costs. But imagine that the government put a tax on movement via such systems so that they cost more to deliver goods than previous methods of transportation. In that case, the great canals and railroads would be rendered as useless as if they had been physically destroyed, and U.S. economic development would have been crippled. Similarly, international tariffs do as much harm to the world economy as would be done by a sinking all the most advanced merchant ships. Thus it was the trade war, initiated by the U.S. Smoot-Hawley tariff bill and similar measures taken by foreign governments that made the Great Depression great.

The creators learned from this. Similarly, they also learned from the debacle of the 1930s what happens when democracies abandon their collective security arrangements and allow tyrants to start picking off their weaker members one at a time. So they put in place something that was called the Free World, within which enterprise and trade could prosper, without fear of either excessive intergovernmental interference or external attack. The result was the greatest period of economic growth that the world has ever seen. America was transformed from poverty-riddled depression America to suburbia America, with a vast middle class owning homes, cars, and televisions and sending their children to college. Europe and Japan were completely rebuilt, with South Korea, Taiwan, and numerous other previously undeveloped countries lifting themselves out of hunger and desperation as well. Furthermore, despite the continued existence of two very dangerous totalitarian potential adversaries, the general peace was preserved.

As a result of this profound success, whatever the differences between the two major parties may have been on other issues, these two fundamental bedrock principles underlying the creation and continuation of the post-1945 world order have remained uncontroversial among serious political leaders for the seven decades ever since.

Unfortunately, this has now changed. In both major parties, powerful figures have arisen who are challenging this long-held consensus. Among the Democrats, the chief usurper is the Marxian socialist Bernie Sanders. Among the Republicans, it is the national socialist Donald Trump. Both would gut the Western alliance. Both would wreck the system of global free trade. Both would cause a global depression. Both would unleash the dogs of war. While their rhetoric is quite different, on the central issue of defending or betraying the Pax Americana, the program of both is the same.

It is to be expected that a rabid left-wing socialist like Bernie Sanders would support such a program, and one must be thankful that the remaining Atlanticist forces within the Democratic Party appear to have him and his faction in check – at least for this election year. But what can one say of the Republicans and allegedly “right wing” radical Donald Trump? National Review founder William F. Buckley used to say that conservatives should support the most conservative electable candidate. Hillary Clinton would continue the Obama administration’s deleterious liberal policies for four more years. So she is certainly no conservative. But Donald Trump would destroy the Western alliance and the world economy. On the basis of that comparison, if the two were to face off in November, as incredible as it may seem, William F. Buckley would have no choice but to vote for Clinton. Surely we can do better.

Is the Pax Americana worth preserving? Do we prefer the world as it has been since 1945 to the world as it was before 1945? Will the Republican Party still fight to help preserve and improve that world? Or will its epitaph be Present at the Destruction?

Dr. Robert Zubrin is president of Pioneer Energy of Lakewood, www.pioneerenergy.com Colo., and the author of The Case for Mars. The paperback edition of his latest book, Merchants of Despair: Radical Environmentalists, Criminal Pseudo-Scientists, and the Fatal Cult of Antihumanism, was recently published by Encounter Books.