BLOOMINGTON, Ind. — Pete Buttigieg committed Tuesday to putting the United States back in the Iran nuclear deal and the Paris climate agreement if elected president and pledged to support a repeal of the war powers resolution passed after the 9/11 terrorist attacks in the first major foreign policy and national security speech by a 2020 Democratic candidate.

Buttigieg, an Afghanistan War veteran, chided President Donald Trump for conducting foreign policy “impulsively, erratically, emotionally,” including what he described as exchanging “love letters” between the president and North Korean dictator Kim Jong Un.

Calling for the winding down of U.S. wars, Buttigieg said he feared the nation would soon have its first combat death of “the 9/11 war who was born after 9/11.”

“As someone who deployed to that war on the orders of a president — who believed, way back in 2014, that our involvement in Afghanistan was coming to an end — the time has come for Congress to repeal and replace that blank check on the use of force and ensure a robust debate on any future operations,” Buttigieg said.

The war powers resolution passed soon after Sept. 11, 2001, known as an Authorization for Use of Military Force, has been a hot-button issue in Washington for years. Lawmakers of both parties have conceded its insufficiency to address the current array of national security threats but have been unable to muster the political support needed to replace it.

Under U.S. law, Congress is supposed to authorize any long-term use of America’s military overseas. The 2001 law authorized U.S. military action against Al Qaeda “and affiliated groups.” That last phrase has become a catch-all used to justify U.S. military action against the Islamic State group, extremist groups across Africa and other threats never foreseen when lawmakers crafted the 2001 legislation.

Still, Buttigieg did not elaborate on what he would hope to see in a new war powers resolution, nor how he might overcome the political obstacles that have prevented the adoption of a new one for years.

Taking subtle aim at former Vice President Joe Biden, Buttigieg argued that the U.S. needed to look forward in its national security strategy, rather than returning to calmer times that predated Trump. Biden has claimed in recent days that if and when Trump is defeated, Republicans will return to the way they acted in years prior to Trump’s election, “because they know better.”

“Democrats can no more turn the clock back to the 1990s than Republicans can turn us back to the 1950s,” Buttigieg said. “And we should not try.”

Biden, campaigning in Iowa on Tuesday, was pushing back on that argument, though he didn’t mention Buttigieg by name. In remarks prepared for delivery in Davenport later in the day, Biden plans to say that while “some people think that’s a return to the past, I don’t see it that way.”

“I see it as embracing the enduring values that have made America, America,” Biden will say. “I don’t think that’s taking us into the past. For me, it’s the only way America is going to have a future.”

Buttigieg, the mayor of South Bend, Indiana, has been leaning in on his background as an intelligence officer in the Navy Reserve to illustrate his readiness to serve as commander in chief despite being only 37 years old. Neither Biden nor Trump served in the military; both received deferments during the Vietnam War.

In his speech, delivered at Indiana University, Bloomington, Buttigieg criticized those who would politicize the U.S. relationship with Israel but also said it was not being disloyal to Israel to criticize its “right-wing government.” He said “it will be our policy” to support a two-state solution to the Israeli-Palestinian conflict, amid questions about whether the Trump administration’s Mideast peace plan will envision Palestinian statehood.

And in remarks aimed directly at Israeli Prime Minister Benjamin Netanyahu, who has vowed to annex Israeli settlements in the Palestinian-claimed West Bank, Buttigieg issued an ultimatum:

“He should know that a President Buttigieg would take steps to make sure that American taxpayers won’t help foot the bill,” he said.

Describing his proposed response to Russian interference in the 2016 election, he said he intended to address “the real weaknesses the Russians exploited — not just the gaps in our technology but our capacity to be too easily turned against each other.” Buttigieg also cast climate change as a national security issue, rather than simply a domestic one, and affirmed his support for a carbon tax to rein in U.S. emissions of heat-trapping gases.

He blasted Trump for embracing autocrats, “alienating democracies and allies,” undermining U.S. treaties and using tariffs “as tantrums” — a reference to Trump’s recent threat to hit Mexico with tariffs unless it stepped up action to curb the flow of immigrants across the southern border.

“The pattern is that decisions are made impulsively, erratically, emotionally, and politically — often delivered by early morning tweet,” Buttigieg said.

Yet Buttigieg’s critiques of presidential handling of foreign policy were bipartisan, and while he didn’t mention former President Barack Obama by name, he suggested that the last Democrat to hold the office had not been unswerving on the world stage, either.

“Since the election of the current president, the United States has hardly had a foreign policy at all,” Buttigieg said. “And lest that seem like a partisan jab, I should add that for the better part of my lifetime, it has been difficult to identify a consistent foreign policy in the Democratic Party either.”