President-elect Trump has repeatedly discussed making Canada the “51st state.” He may be joking, but there’s truth in humor: American annexation would benefit both countries. The example of British unification highlights how North American union could precipitate a new era of prosperity.

At the dawn of the 18th century, the United Kingdom did not exist. England and Scotland shared a language, political system, and international alliances, but remained independent. Division disadvantaged both nations. Economically, separation limited cross-border trade, hindering internal growth.

Politically, Scotland became a hub for Jacobite supporters of the deposed Stuart dynasty, who sought to impose absolutism on England. Strategically, the Royal Navy was forced to defend the Scottish coast without financial support, while Scottish citizens and ships abroad were left defenseless.

Yet British unification remained stymied. The Scottish public feared the loss of its cultural identity. Politicians worried that their influence would be lessened in a united Britain, while merchants resented English competition.

Then, Scottish mismanagement and English action forced change. In Scotland, poor harvests led food prices to rise 150 percent, while failed investments nearly bankrupted the government.

Parliament responded by passing the Aliens Act of 1705, which threatened to embargo Scottish trade unless Scotland agreed to unification. The Scottish economy was weak, and almost half of Scottish trade was with England, so the Scottish parliament was forced to negotiate. The United Kingdom was formed two years later.

The long-term benefits were clear. The removal of internal trade barriers helped power the industrial revolution, centered in southern Scotland and northern England. Strategically, unification gave Britain the military power needed to beat France in the Seven Years and Napoleonic Wars. Britain went from being divided and weak to the world’s first superpower.

Like England and Scotland, the United States and Canada share a border, a common language — except for Quebec — and similar systems of government, yet remain disunited. As in Britain, though, division doesn’t benefit either country.

Economically, trade barriers raise the price of cross-border transactions by 30 percent. Politically, Canada has been infiltrated by both Chinese and Indian intelligence services, threatening American national security. Strategically, Canada’s lackluster military spending forces American taxpayers to pay for its national defense.

Meanwhile, domestic mismanagement has cratered the Canadian economy. While America’s output per capita has risen by 23 percent over the last decade, Canada’s has risen by a measly 2 percent. Since 2005, housing prices have risen twice as fast in Canada as in America. Under Prime Minister Trudeau, oil production has increased by only half as much as in America.

Canada’s economic failures create the perfect opportunity for America to pursue bringing Canada into our union. Canada is even more dependent on American trade than Scotland was English: More than 80 percent of Canadian exports go to the United States. America should take a page from Britain and insist that Canada join America by linking President Trump’s threatened 25 percent tariff to North American unification.

Even if Canada’s central government resisted, tariffs could still force unification. Many Canadian provinces export more to the United States than they do to the rest of Canada. By offering to make individual provinces states, America could facilitate Canadian breakup. Tidings of this can already be seen in attempts by provincial Premiers to negotiate separately on trade.

Doing so would deliver key benefits. British unification helped spark the industrial revolution by merging Scottish and English coal deposits and linking regional economies. North American unification could revitalize American and Canadian industrial bases by connecting auto industries in Ontario and Michigan. Reducing regulations on Albertan oil reserves would cut energy costs. Eliminated trade barriers would create hundreds of billions in consumer surplus.

Likewise, the Act of Union strengthened Britain’s international position. By combining Scottish and English populations, it created a powerful military that went on to win every major Anglo-French conflict over the next two centuries save the American Revolution. Unifying North America could similarly strengthen America’s position against Communist China.

Some will doubtlessly object to the idea of America “strong arming” Canada. The European Union, though, has long excluded non-members from its trade zone while linking economic benefits to political union. There’d be no difference in principle for America to do the same.

Anglo-Scottish unification changed world history. By uniting two similar but divided nations, it spurred the industrial revolution, safeguarded English liberties, and strengthened Britain’s geopolitical position. By imitating English tactics, America could likewise rewrite the course of the 21st century for the better.