MADRID – Ten years ago, during his first trip to Europe as US president, Barack Obama delivered an historic speech in Prague. Much to the delight of the crowd, Obama described a world free of nuclear arms as being both desirable and within reach. That declaration was unprecedented for an American president, and would contribute to his winning the Nobel Peace Prize later that year.

Obama also used the occasion to reassure Czechs – and Europeans generally – that the United States would never turn its back on them; that its commitment to the principle of collective defense under Article 5 of the North Atlantic Treaty was permanent and unconditional. Those words now seem like a relic of a bygone era.

Obama’s successor, Donald Trump, has questioned that key pillar of NATO, departing from almost 70 years of diplomatic tradition. Worse, he recently announced his intention to withdraw the US from the Intermediate-range Nuclear Forces (INF) Treaty with Russia, which has been fundamental in guaranteeing European security since 1987. And though the Obama administration did end up deprioritizing nuclear disarmament over time, Trump seems to have replaced that goal with its polar opposite: rearmament.

To be sure, bilateral agreements like the INF Treaty – an artifact of the late Cold War – are no longer sufficient in today’s multipolar world. While the US and Russia are forbidden under the treaty from possessing land-based missiles with a range of 500-5,500 kilometers (300-3,400 miles), an estimated 95% of China’s missile arsenal now comprises precisely such weapons.

Moreover, the US and Russia have both accused the other of violating the INF Treaty, implying that the agreement has become moot anyway. But a far more sensible US strategy would have been to reaffirm its commitment to the treaty, thereby pressuring Russia to do the same in light of its own presumed violations. By taking the high ground, the US would have been far better positioned to extend the same normative framework to China and its arsenal.

Instead, the author of The Art of the Deal has followed the advice of someone who has yet to meet a deal he didn’t want to tear up: Trump’s national security adviser, John Bolton. Having already dispensed with the 1972 Anti-Ballistic Missile Treaty in 2002, during his tenure in President George W. Bush’s administration, Bolton has used his position in the Trump administration to launch attacks against the INF Treaty and the Joint Comprehensive Plan of Action (JCPOA) with Iran. Most likely, his next target will be New START. Signed by Obama and then-Russian President Dmitry Medvedev in Prague in 2010, that nuclear arms reduction treaty will expire in 2021, barring an agreement on its extension.

With the steady collapse of the international arms-control architecture has come a fresh race to develop new types of nuclear weapons. The potential use of these weapons is now discussed with such frivolity as to foreshadow a return to the darkest days of the Cold War, but one that is even more dangerous, because other countries not subject to the Non-Proliferation Treaty (NPT), such as North Korea, have since joined the nuclear club.

During Trump’s first year in office, his incendiary public exchanges with North Korean leader Kim Jong-un brought relations between Washington, DC, and Pyongyang to their tensest point in decades. While Trump has since abandoned his threats of "fire and fury” and given diplomacy a chance, his administration’s approach to North Korea has ignored all of the canons of effective diplomacy. This has given rise to another kind of frivolity: the spectacle of vacuous praise.

In the end, the lack of consensus among US foreign policymakers and the misaligned expectations of the two negotiating parties, combined with Trump’s own improvisations, condemned his recent summit with Kim to failure. A reorganization is now urgently needed, particularly to incorporate the other regional powers and keep Bolton and other hawks in the administration from derailing the process further.

Meanwhile, India and Pakistan, two other NPT non-signatories, recently engaged in a cross-border military confrontation, following a terrorist attack last month in the Indian state of Jammu and Kashmir. Once deemed "the most dangerous place in the world” by former US President Bill Clinton, Kashmir is essentially shared between three nuclear powers: India, Pakistan, and China. Not since Pakistan revealed its nuclear capacity to the world in the late 1990s have Indian-Pakistani relations been so tense. Worse, as the latest instability shows, the presence of nuclear weapons is not sufficient to prevent conflict. Instead, it merely raises the risk that quarrels will escalate into existential conflagrations.

Lastly, in the Middle East, the Trump administration has actively sowed the seeds for nuclear proliferation. The decision to abandon the JCPOA was entirely counterproductive, merely reflecting Trump’s blind support for Israel – another NPT non-signatory – and Saudi Arabia. Indeed, the Trump administration is even exploring the possibility of exporting nuclear material to the Saudi regime without putting the necessary safeguards in place.

Apparently, Trump is not bothered by the fact that Saudi Crown Prince Mohammed bin Salman has neither ruled out developing nuclear arms nor committed to a strict regime of inspections by the International Atomic Energy Agency. One false step, though, could plunge the Middle East into a nuclear arms race – truly a worst-case scenario for such a fraught region.

During the 2016 presidential campaign, Trump raised a red flag for the umpteenth time when he suggested that Japan and South Korea should develop their own nuclear weapons as a means of self-defense. This idea couldn’t have been more wrongheaded. Logic dictates that if more countries acquire nuclear weapons, the likelihood of such weapons being used will increase.

The Cold War gave us a glimpse of the risks we run when our single-minded pursuit of some geopolitical interests causes us to lose sight of the most important of them all: international security. As Obama emphasized ten years ago in Prague, the US is the only country ever to have used nuclear weapons, and therefore has an historic responsibility to ensure that they are never used again. For the US to forsake this responsibility and champion a new era of nuclear proliferation would be a tragic outcome.

The writer is currently President of the ESADE Center for Global Economy and Geopolitics, Distinguished Fellow at the Brookings Institution, and a member of the World Economic Forum’s Global Agenda Council on Europe.

Copyright: Project Syndicate.