President-elect Donald Trump talks to members of the media on Dec. 21 as retired U.S. Army Lieutenant General Michael Flynn stands next to him at Mar-a-Lago estate in Palm Beach, Fla. (Carlos Barria/Reuters)

President-elect Donald Trump has stacked his Cabinet with military generals, pushed for more Pentagon spending and a bigger Navy, threatened to slap tariffs on China and Mexico and, last week, suggested that he was open to expanding the U.S. nuclear arsenal.

The aim, he has said, is to achieve “peace through strength.”

If Trump follows through with this confrontational approach, it will represent a sharp break with the multifaceted foreign policy strategy that both Democratic and Republican presidents have practiced for decades, including reliance on what diplomats call “soft power” to achieve objectives and avoid conflict. Instead, Trump views foreign policy as largely transactional, aides say, and his goal is to win — by speaking loudly and carrying a big stick.

But critics, including former Obama administration officials and foreign diplomats, said winning on the world stage requires more than bluster and intimidation and pugilistic messages on Twitter. American leadership, they said, also is about the carrots — the promotion of democratic values and building U.S.-led institutions that can address shared global challenges such as economic growth, climate change and terrorism.

“If your slogan is, ‘America first,’ other people will think, ‘What about me?’ ” said Joseph Nye, who was an assistant secretary of defense under President Bill Clinton.

Past presidents have tried to use “soft power” strategies to bolster the United States’ cultural appeal abroad and lend moral weight to the country’s standing as the free world’s leading alternative to communist or authoritarian systems. Such tactics are not a substitute for military and economic “hard power,” foreign affairs analysts said, but can help shape global perceptions of the United States and its motives.

President Obama, for example, spoke frequently about the need for an international order based on universal human rights and the rule of law as he pursued the Paris climate accord, a Pacific Rim free-trade pact and the Iran nuclear deal.

By comparison, Trump has seldom talked about such ideals, either during the campaign or since winning office. He has expressed skepticism about the international agreements negotiated by the Obama administration, saying they do not do enough to help the American people. This week, Trump tweeted that the United Nations has potential but “right now is just a club for people to get together, talk and have a good time.”

Trump has yet to appoint a foreign policy expert with an extensive background in development assistance or human rights. He has repeatedly questioned the need to cut greenhouse gas emissions globally in order to address climate change, while Obama made that issue a centerpiece of his foreign policy agenda.

Trump’s administration is “all about tough guys and being tough,” said Suzanne Nossel, a former deputy assistant secretary of state for international organizations under Obama. Nossel, now the executive director of PEN America, a literary free-speech group, added that “there’s a great sense of fear around the world that the U.S. is going to abandon its leadership role in the world on behalf of the vulnerable.”

Trump’s aides said his strategy is a necessary course correction to what they called Obama’s “apology tour” of trying to build bridges to rogue regimes in places such as Iran and Cuba.

Obama took office on a pledge to recalibrate the U.S. role in the world and repair the country’s image after President George W. Bush’s “with us or against us” war on terror and the U.S. military campaigns in Afghanistan and Iraq.

Obama sought to build trust between the United States and the Muslim world, and he promised to reach out to despots and dictators if they were “willing to unclench your fist.” The administration restored diplomatic relations with authoritarian regimes in Burma and Cuba after 50 years of isolation in exchange for political reforms.

Ben Rhodes, a deputy national security adviser in the Obama White House, said the president’s collaborative approach and emphasis on international norms helped convince other countries to partner with the United States to do things that were not always popular. He cited the economic sanctions on Iran and Russia, which received less support among some European nations.

“There’s a counter-theory where we should be more strident in telling them what to do or saying ‘with us or against us,’” Rhodes said. “But in this world where power is much more diffuse than it was a decade or two ago, it just doesn’t work any more.”

Trump has threatened to terminate the Iran nuclear deal and Obama’s diplomatic rapprochement with Havana, which included the lifting of some U.S. economic sanctions. And he has named to his administration several former generals with deeply pessimistic views of Iran. The group includes his national security adviser, retired Army Lt. Gen. Michael T. Flynn.

Obama was “high on ideology, low on practicality,” J.D. Gordon, a Pentagon spokesman during the Bush administration who served as a national security adviser to Trump’s campaign, said in an email. “Hostile regimes took full advantage of his olive branches for little to nothing in return. . . . [Trump] doesn’t believe in giving anything away and always strives for the better deal.”

One European diplomat, who spoke on the condition of anonymity to comment frankly about Trump, said: “It is of some concern to listen to these statements, where it seems that there’s less emphasis on the common-value basis and the multilateral structure” of diplomacy.

The diplomat added that “the risk is the U.S. will sort of step back from this leadership, and it will cause certain disarray.”

Peter Feaver, a national security official in Bush’s administration, said American presidents, going back decades, have wielded tools to coax other nations to embrace U.S. objectives without explicit coercion, in hopes of fostering a “more benign view of American power.”

President Ronald Reagan used this approach effectively against the Soviet Union, he said, by promoting a more desirable alternative and supporting dissident campaigns such as the anti-communist Solidarity movement in Poland. George W. Bush pursued widespread development aid and a presidential-level initiative to combat the spread of AIDS in Africa.

But there is a strain in the GOP that is strongly opposed to foreign aid, said Feaver, now a political science and public policy professor at Duke University, and it’s unclear whether Trump will side with this faction.

“We have never had a president who understands branding as well as Trump does,” Feaver said, “and an element of soft power is branding.”

Trump has expressed skepticism of the Bush-era military interventionism, but he also has discarded Obama’s caution over using terms such as “radical Islam” to describe terrorist threats emanating from the Islamic State and Muslim nations.

Obama has warned that such language will perpetuate the terrorists’ goals of inflaming a clash of religions and will radicalize more disaffected young people in the Middle East. Polls show that while the United States is viewed more favorably under Obama than Bush across Europe and Asia, the rebound in reputation has not lasted in the Middle East despite initial enthusiasm for Obama.

Last week, Trump reacted to a deadly truck attack in Germany by labeling it an Islamic attack on Christianity — well before authorities had determined a motive or had a definitive suspect. During the campaign, he proposed a ban on Muslims entering the United States and spoke approvingly of the use of torture on terrorism suspects.

Vali Nasr, who served as a State Department senior adviser for Afghanistan and Pakistan in the Obama administration, accused Trump of “cavalierly dispensing with America’s soft power.”

“The ‘America first’ rhetoric, combined with the anti-Muslim rhetoric, will constrain America’s ability to persuade world powers to work with us,” said Nasr, now the dean of Johns Hopkins University’s School of Advanced International Studies.

Human rights advocates are alarmed by Trump’s professed admiration for authoritarian figures such as Russian President Vladi­mir Putin, whom he called a stronger leader than Obama.

After his election victory, Trump fielded a congratulatory call from Philippine President Rodrigo Duterte, whose administration has overseen the extrajudicial killings of thousands of suspected drug dealers. Obama had canceled a bilateral meeting with Duterte, but Trump invited him to the White House.

But former House speaker Newt Gingrich (R-Ga.), a Trump ally, said there are some instances where Trump might object to persecution of minorities overseas, especially on behalf of Christians.

And there’s a pragmatic side to the president-elect’s transactional approach that could produce results, Gingrich added. He pointed to Syria where Trump has suggested that he is amenable to a deal with the Russians and Syrian President Bashar al-Assad that allows Assad to stay in power while ending the civil war.

The Obama administration has refused such a scenario based on what it sees as Assad’s human rights abuses, including the use of chemical weapons on his own citizens.

“If you wanted to minimize the number of people killed in Syria,” Gingrich said during a Washington Post Live forum last week, “you would’ve supported Assad, because the truth is if Assad had won very quickly, fewer people would’ve died.”