In an unfathomably shocking comeback, former President Donald J. Trump of the Republican Party has declared victory in the 2024 United States presidential election.

This was a revenge match for Trump, who lost his bid for reelection in the 2020 presidential race. He is now just the second president in history to have been reelected following a failed bid to stay at the White House.

Vice President Kamala Harris of the Democratic Party, who sought to become the nation's first woman president, could not break the glass ceiling.

"We made history," Trump said in front of his supporters, along with a promise to "make America great again."

Trump secured support by fanning the flames of discord between conservatives and liberals, Republicans and Democrats, in a scheme to divide people up between friends and allies.

Trump widened gulfs between white and non-white Americans, elites and non-elites, and intensified debate over diversity. It's feared that the country is progressing toward firmly becoming an intolerant society.

"We will heal America," Trump said. However, was it not Trump himself who deepened the divides?

What will happen to US democracy?

Let's recall the election four years ago. Trump attempted to overturn the results, claiming that they were rigged, and a number of court battles unfolded. His supporters eventually stormed the Capitol in an unprecedented attempt to interfere with the transition of power, leaving an ugly scar on the history of the country.

When Trump faced prosecution over the attack, he shuffled blame onto the Joe Biden administration, claiming the Democrat was using the Department of Justice to eliminate political opponents.

Does Trump's reelection mean the U.S. electorate has overlooked those events which jeopardized democracy? Not necessarily.

According to exit polls by U.S. media, three in four voters were expressing their dissatisfaction and anger with the current state of affairs, a sign of distrust of the Biden administration.

Trump seized upon current issues like rising prices that have pained American families and a surge in illegal immigration, claiming that the Democrats "destroyed the country."

Even if supporters saw Trump's claims as problematic, they likely viewed a continued Democrat regime as even harder to accept.

This is a major hit for the Democratic Party. After support spiraled down, the party forced President Biden to withdraw from the race and quickly endorsed Harris as the next presidential candidate. It cannot be denied that there was a serious lack of preparation. Some aired concerns that the lack of a primary race to determine the candidate ran against democracy.

Divisions in the United States of America are at a critical point. The election saw repeated personal attacks alleging things such as "Trump is a dictator" and "Harris is a communist," laying bare a mutual antipathy.

Differences of opinion between conservatives and liberals on issues such as abortion, gun restrictions and same-sex marriage deepened to the point of hatred. Both sides claim justice and are unforgiving of concessions. If conflict continues to mount, things could hit a point of no return where the divisions will be difficult to mend.

The result is expected to also have a major impact on diplomacy. The world is facing wars in Ukraine and the Middle East along with a military threat from China and North Korea. Until now, U.S. economic and military power has been second to none, but the country's power has been waning ever since the attacks of 9/11.

A new test for US allies

Make no mistake: Trump's second term will only speed up that trend. Holding up his "America first" policies, illegal immigrants, not China and Russia, will be seen as the threat, and diplomacy will become a secondary issue.

Trump is dragging his feet on supporting Ukraine against Russia's invasion, calling on European states to do more. He also shows no sign of admonishing Israel for its expanding fronts in the war against Hamas.

Trump views America's network of allies more as a burden than a resource, to the point of even hinting at exiting NATO. He even views national security through a cost-benefit calculus, and may ask partner nations to pay additional costs for things such as the operation of overseas U.S. military bases.

Trump's way of diplomacy is ad hoc, but he has been consistent in taking a careful stance when it comes to military interventions. Economic warfare, on the other hand, is his primary arena for battle.

Trump has expressed the desire to place high tariffs on all imports, as high as 60% for those from China. This would be an extreme protectionist policy that weaponizes trade.

There is also a fear that populism will spread further in Europe and elsewhere in response to Trump's America-first foreign policies. If democratic nations thin out, it will be a gain only for despotic states such as China and Russia.

How should Japan handle this situation? U.S. leadership remains crucial for resolving global challenges and conflict. Japan must continue to insist that, along with European countries, the U.S. fulfills its responsibility.