Mr. Kim needs to be convinced that such a scenario is credible. Joint U.S./South Korean military exercises is one way to send that message. Another is for President Trump to ask the Pentagon to give him a new report on military options. Implementation would be a last resort, of course, but not an unimaginable one. On the contrary, as Gen. Joseph Dunford, the chairman of the Joint Chiefs of Staff, said almost two years ago: “What’s unimaginable to me is allowing a capability that would allow a nuclear weapon to land in Denver.” If we do not prevent Mr. Kim from acquiring nuclear weapons that he can deliver to American cities (and/or use for blackmail), efforts to prevent the Islamic Republic of Iran from following suit are sure to fail as well. The list of rogue and adversarial nuclear-armed powers will grow thereafter. Years ago, we should have started seriously preparing for such a disastrous contingency. How better to establish deterrence than with a comprehensive missile defense system capable of shooting down any missiles launched anywhere in the world? Such a system is technologically feasible. No treaties restrict us. But for decades, American leaders, Republican and Democratic alike, have dawdled, procrastinated or insisted that robust missile defense is too expensive. Is it? Rebeccah Heinrichs, a missile expert at the Hudson Institute, said. “Consider the value of what you’re protecting. Compare that to the cost of the missile defense system.” What will it cost to rebuild Denver, New York, Washington or Los Angeles following a nuclear attack that we failed to prevent?

I’m rooting for those within the U.S. government who will argue that it’s time to apply sticks, rather than dangle carrots, time to begin a “maximum pressure” campaign ? an option Mr. Trump favored then shelved prior to the Singapore summit last June. Could maximum pressure lead Mr. Kim to the conclusion that nuclear weapons imperil rather than protect his dynasty? We’ll never know unless we try. Among the many actions now required: Imposing harsher and more comprehensive economic sanctions, and severing North Korea’s connections to the international financial system. Chinese and other non-Korean banks now conducting illicit business with the Kim regime need to be sanctioned as well. North Korean laborers abroad are virtual slaves. Their living conditions are horrific, and the Kim regime skims hundreds of millions of dollars from their paltry pay checks. U.N. Security Council Resolution 2397 mandates the expulsion of all such workers by 2019. But most governments won’t meet their obligations unless they feel diplomatic pressure from the United States and ? this would be nice ? from U.S. allies. Also, U.N. sanctions prohibiting North Korea from obtaining oil and fuel through ship-to-ship transfers can’t be enforced without enhanced surveillance, patrols and interdictions. North Korea uses its embassies and other diplomatic outposts to engage in covert commercial and financial activities. American diplomats need to persuade host governments to crack down. What else, beyond this economic squeeze, should keep Mr. Kim awake at night? In Singapore, Mr. Trump showed him a 4-minute video promoting the benefits if he gives up his nukes and pursues peace, security and economic prosperity with energetic American support.

There has been a lot of misinformation about both getting out of the so-called Iran deal and getting into a new North Korean agreement. The two situations may be connected, but not in the way we are usually told. Getting out of the Iran deal did not destroy trust in the U.S. government. In 2015, the Iran deal was not approved as either a Senate-ratified treaty or a joint congressional resolution. Had the deal been a treaty, President Trump could not have walked away from it so easily and with so little downside. A cynical North Korea knew only too well that in the past, Mr. Obama either entered into agreements or avoided them based on his therapeutic notion that human nature was both changeable and essentially noble. The North Koreans now seem worried that a more unpredictable Mr. Trump has a quite different, pessimistic and tragic view that humans are predictably capable of almost anything ? if not strongly deterred. International sanctions work slowly. But despite occasional cheating, they do in the end work well enough to injure economies. The tragedy of the 2015 Iran deal was that an embargoed Tehran had been brought to the brink of social and economic chaos before the deal was struck. In both the Iran deal and a potential North Korea deal, the United States has enormous leverage ? and it should never forget that fact. Global sanctions can wreck the relatively small and vulnerable Iranian and North Korean economies. Even American sanctions alone and the ripples from them can injure Tehran and Pyongyang. The U.S. can also deter Iran and North Korea in a variety of other ways. In sum, for all their obnoxious bluster, the rogue governments of North Korea and Iran are more vulnerable than ever.

Mounting debt, hyperinflation, serial devaluations and capital flight are perennial drags on the economy, as are bloated bureaucracies and continuing corruption. Nevertheless, Argentina’s economy is the third largest in Latin America. And, of course, the country is much healthier ? economically, politically, in many ways ? than oil-rich but tragically impoverished Venezuela. Argentina also is wealthier ? not to mention freer ? than Cuba. All this strikes me as fascinating in itself. But I find it instructive as well, not least because, in the United States today, so many people on both the left and the right exhibit aspects of Peronist thinking. In particular, “victim-politics populism”, an attraction to fanaticism, and the cultivation of grievances, the belief that whatever you lack must have been taken by evil “others.” Also echoing Peronism is the failure, mainly on the left, to distinguish between rights and social benefits. Rights can be guaranteed by virtually any government. Social benefits can be provided only by economic systems that produce wealth year after year. Socialism never achieves that. What does? The creation and maintenance of an opportunity society; policies that encourage entrepreneurship, innovation, risk-taking investment, enterprise and the flourishing of the individual and family. In one of Buenos Aires‘ great and gaudy theaters, I attended a spectacular tango show. It ended with newsreel footage of Eva Peron projected on a big screen behind an entertainer with a pencil moustache singing “Don’t Cry for Me Argentina.” Many members of the audience took to their feet to applaud and cheer. I found that fascinating and, again, instructive.

In 1946, they elected Juan Domingo Peron president. His young wife, a former actress, quickly became the object of a personality cult. “Evita” ? celebrated in an eponymous 1979 Broadway musical and a 1996 motion picture starring Madonna ? grew up poor and cared about the poor. Whether she helped the poor is a separate question. She famously said: “One cannot accomplish anything without fanaticism,” a thesis perhaps not based on a thorough reading of history. Argentina’s congress gave her an official title: “Spiritual Leader of the Nation.” Not long after, in 1952, at 33 years of age, she died of cancer. Three million people attended her funeral. The ideology that came to be known as Peronism was a not-so-distant cousin of fascism, Italian-style. Socialist and nationalist, it stressed social justice ? an infinitely flexible phrase ? and the empowerment of the working class at the expense of those labeled exploiters and oppressors. In practice, that meant forced industrialization, income redistribution, government subsidies, protectionism and import substitution. Such policies proved unproductive. At the same time, unchecked government power facilitated corruption, further limiting economic development. President Peron was overthrown by the military in 1955. Over the decades that followed, he would be re-elected (twice), as would other politicians who proudly called themselves Peronists. There also would be additional periods of military rule. In the 1970s and early ‘80s, a particularly bloody junta “disappeared” an estimated 30,000 dissidents, unionists, students, writers, artists and others. Argentina’s per capita GDP today is less than a third that of Canada.

Why isn’t Argentina as wealthy as Canada? For that matter, why are all the countries of Latin America, without exception, so much less prosperous than their neighbors to the North? Anyone attempting to write a brief essay on the disparity between Latin America on the one hand, and the United States and Canada on the other, will be tempted to look for a single-cause explanation. The reality is almost certainly more complex ? an equation combining history, culture, economics and politics. Latin America “was not poorer to start with, in the seventeenth century,” wrote Harvard Professor David S. Landes in his landmark 1998 study, “The Wealth and Poverty of Nations: Why Some Are So Rich and Some Are So Poor.” On the contrary, “The Spanish and Portuguese invaders thought of their English rivals as orphans of destiny.” In the Southern Hemisphere, there was gold and silver for the taking. In the North, there was wilderness. “The best the English could do was lurk like jackals on the flanks of the Spanish bullion fleets while their colonists struggled to survive in a hostile environment.” Of all the nations in Latin America, Argentina seemed the most promising. After breaking from Spain and achieving independence in 1816, immigrants poured in from Europe, Italy especially. Argentina had fertile soil, and climates ranging from subtropical to temperate to subpolar. From about 1870 to 1930 there was a golden age during which Argentina’s per capita GDP was neck and neck with Canada‘s. After that, however, and despite sitting out World War II, Argentines began to make unwise choices.

Our allies and partners want to “buy American.” They know U.S. industries produce the most technologically sophisticated and effective defense systems in the world. When our allies and partners are better equipped to defend themselves, there is greater regional peace and stability ? and far less need for American service members to be in harm’s way. For too long, we have made it too hard to provide our allies and partners with the defense capabilities they require and that are in America’s interests. That’s why the Trump administration announced Thursday two landmark policies aimed at reforming the international sale of U.S.-produced arms and the export of unmanned aerial systems (UAS). As Mr. Trump works to balance our trade with the rest of the world, further strengthening a critical part of our export economy and defense industrial base is a logical and critical step. The international sale of American-made military and commercial UAS offers an important tool to take this step. The UAS sector represents one of the most dynamic emerging areas of defense technology. Although the U.S. leads the way in UAS technology, overly restrictive policies enacted by the previous administration have accelerated an undesirable outcome: Strategic competitors like China are aggressively marketing to and making sales in international markets that are forecast to be worth more than $50 billion a year within the next decade. The Trump administration’s UAS export policy will level the playing field by enabling U.S. firms to undertake direct sales to authorized allies and partners. By expanding international sales opportunities, American industry will be further incentivized to do what it does best ? invest and innovate. This will keep our defense industrial base in the vanguard of emerging defense technologies.

Critics know what’s wrong with the European Union. It suffers from what they call a “democratic deficit.” Democracy is often loud, usually messy and everyone gets a voice. This is inconvenient for the elites and the bureaucrats. The unelected Eurocrats embrace all the politically correct positions on climate change, capital punishment, immigration and genetically modified foods, but they know in their hearts they’re acting against the hopes and wishes of many ordinary Europeans. The Eurocrats in Brussels issue regulations, overrule local taxing officials and pass judgment on member states’ fidelity to classic-liberal political ideals. Bureaucrats in Europe, like those here, never have to face a voter. This disease at the heart of the European project is getting a fresh look in the stand-off between the powers-that-be in Brussels and the popular government in Hungary. Prime Minister Viktor Orban, an immigration skeptic whom the European left loves to hate, won a remarkable victory in the parliamentary elections April 8, winning a third four-year term. To the consternation of his critics, Mr. Orban refuses to toe the line laid down by the bureaucrats in Brussels on immigration. He argues that the flood of unchecked migrants poses both a security and a cultural problem for Hungary. He is accused of peddling prejudice against Islam because he appeals to the traditional Christian values echoed across the region. What the critics can’t see is that, whatever else Mr. Orban’s victory was, it was not undemocratic. Mr. Orban and his allies won because they got the most votes. That’s how elections work, which losers there, like here, have trouble understanding. Populism, particularly conservative populism that doesn’t mock voters’ long-held beliefs and values, turns out to be popular with most voters.

Pyongyang recently fired off a “‘new-type tactical guided weapon’ developed by an institute responsible for [North Korea]’s missile program.” The new weapon, experts suspect, could have been a variant of a short-range ballistic missile called the 9K720 Iskander. And sure, Kim Jong-un’s latest provocation represented a stark break from the happy talk and placidity that has constituted the last 18 months of U.S.-South Korean-North Korean relations. In truth, the North’s test is further evidence that “the process” ― diplomatic detente and subsequent talks among South Korea, North Korea and the United States ― is breaking down, if not fully broken down altogether. Mr. Moon, who has staked his presidency on warming relations between the Koreas, is having a hard time even getting a meeting with Mr. Kim. The dormancy, if not death, of the denuclearization discussion is hardly cause for despair: The focus on denuclearizing North Korea has always been myopic. The North’s weapons programs are a symptom of the underlying rot of the regime, not the disease itself. Its nuclear program has demonstrated that the Kim regime has been willing to devote huge resources to arming itself with weapons that could kill millions while simultaneously allowing hundreds of thousands of Koreans to starve to death. The regime makes no secret of the fact that its goal is the reunification of the two Koreas ? under its rule. Yes, nuclear weapons serve to strengthen the regime. In a sense, then, Mr. Kim did the world a favor by testing a weapon. He reminded a forgetful world of the character of his regime. A nuclear or ICBM test would be even more of a memory-jogger.

Being a diplomat for the world’s most undiplomatic regime must be an odd job. North Korea’s foreign service officers posted in the country’s embassies abroad don’t do much of the feel-good factory tours and rubber chicken dinner hobnobbery that characterize the daily lives of most countries’ ambassadors. Instead, North Korea’s diplomats are more like mafioso, charged, above all, with bringing in money for the regime. Each North Korean embassy is reportedly ordered to bring in a certain quota of foreign cash ? although its embassy in Rome appears more concerned with illegally importing luxury goods for the Kim regime to enjoy while its people suffer. North Korean diplomats posted to European capitals are often involved in circulating counterfeit cash and black market cigarettes. In Africa, they’ve been busted smuggling rhino horns and ivory. The North Korean embassy in Beijing, which takes up an entire city block, even houses dormitories where waitresses at sanctions-busting North Korean-owned restaurants live. Proponents of restarting engagement between North Korea and the United States have suggested opening diplomatic ties as a step the two sides could take to get what’s inevitably known as “the process” rolling along. To open “liaison offices” ? embassies in all but name ? is thought of as a relatively modest step, much less drastic than, for instance, lifting sanctions. But given the activities of North Korea’s diplomats, that’s hardly the case. A North Korean embassy in the heart of Washington would inevitably become a locus of espionage and criminality. Yet recent events in Madrid suggest that opponents of the regime may actually derive some benefit from North Korea’s embassies.