Donald Trump has said many outrageous things in the course of his campaign to be the Republican nominee for President, whether it be his equivocation over condemning the Ku Klux Klan, or his derogatory attacks on women who dared to question him, but arguably the most disturbing of all his comments was his insistence that he would force the US military to follow his orders, even if those orders were to break international law. He had made those claims many times over the last few months and again repeated that assertion at Thursday’s raucous GOP debate in Michigan, before rowing back barely 12 hours later in a statement issued saying that he does “understand that the United States is bound by laws and treaties” and that he would “not order our military or other officials to violate those laws.”

Hopefully that is the last we hear on the matter, but throughout the campaign, whether it be in advocating torture or in his comments about forcing Mexico to fund his famed wall, Trump has frequently shown contempt for international law and treaties. It is part of a deliberate strategy to encourage rage against the established order in America, and stoking that anger has driven the Trump phenomenon. At the same time Trump has frequently praised Vladimir Putin whilst displaying disinterest in NATO and the future of the transatlantic alliance, encouraged American isolationism and proclaimed dissatisfaction with current WTO rules. Trump’s central tenet seems to be that not only has the current American system failed ordinary Americans, the entire global governance system of international law and trade which America set-up in the wake of World War Two is also no longer in America’s interest.

That rejection of the global system and the principles the Western world has promoted for the last 70 years poses an existential threat to the unity and power of the West, just at the time its dominance is being challenged from the East. If a Trump presidency followed through on many of his public comments over the last year it would be an economic and political disaster for Americans and Europeans. That’s a big if, but complacency and underestimating Trump has proven to be fatal to his political opponents so far. In the immediate future a Trump presidency would likely spell the end of the Transatlantic Trade and Investment Partnership agreement, a unique opportunity for the West to set the global standards and terms of trade by unifying into the biggest free trade area the world has ever seen. Consumers will immediately be denied the job boosting and price lowering potential of TTIP.

Aside from short-term economics Trump’s disinterest in his traditional partners risks furthering instability in Europe and splintering key alliances that have maintained peace in the west since World War Two. NATO has been the key guarantor of our mutual security, and a Trump-led retreat would not only pose an immediate danger to those members being threatened by a resurgent Russia with contempt for international law, it could undermine the military credibility of the entire alliance. Trump cannot assume his actions will provoke no reaction, and lazy anti-Americanism has always had residual support in Europe. An American withdrawal from a strong security partnership would give succour to all those forces ranged against the Western alliance, not least the current leader of the Labour party. The consequences of that are almost impossible to predict.  The UK, and Europe, now more than at any time since the Iron Curtain fell, need an America leading and engaging in the Western alliance, promoting our joint commitment to international law and free trade.