Former Secretary of Defense and director of Central Intelligence Leon Panetta on Wednesday made what was so far one of the most compelling cases for why Donald Trump is unfit to lead U.S. forces at home and abroad as commander in chief.

But in a sign of how opposed many Democrats are to America’s continued participation in conflicts across the Middle East, Panetta was drowned out by chants of “No more war!” near the end of his speech to the Democratic National Convention in Philadelphia.

Panetta’s address was sharply partisan, built upon making the case that Trump is unqualified to command U.S. military forces. “The president, a commander in chief, has no greater responsibility than the decision to send our troops into harm’s way,” Panetta said.

“Donald Trump asked our troops to commit war crimes, endorses torture, spurns our allies and suggests that countries have nuclear weapons. And he praises dictators from Saddam Hussein to Putin.”

Panetta, who has worked with nine presidents in a career that spans more than 40 years, also seized on comments Trump made earlier Wednesday, when Trump said he hoped Russian hackers would uncover emails that Democratic nominee Hillary Clinton had deleted.

“Today, once again, [Trump] took Russia’s side, and he asked the Russians to interfere in American politics,” Panetta said.

“Donald Trump, who wants to be president of the United States, is asking one of our adversaries to engage in hacking and intelligence efforts against the United States of America? To affect an election? It is inconceivable to me that any presidential candidate would be that irresponsible,” he said.

“In an unstable world, we cannot afford unstable leadership,” Panetta said, referring to Trump. “We cannot afford someone who believes America should withdraw from the world, and someone who threatens our international treaties and who violates our principles. We cannot afford an erratic finger on our nuclear weapons.”

Yet even as Panetta challenged Trump, the Democratic delegates on the convention floor challenged Panetta, chanting “No more wars!” as soon as Panetta said the U.S. should not “withdraw from the world.”

To many on the left, those words sound like a carte blanche for the U.S. to engage in foreign conflicts, a deeply unpopular sentiment on both sides of the political spectrum.

Panetta’s address was part of a largely successful effort on Wednesday to portray Hillary Clinton as a capable commander in chief. This goal was exemplified by the fact that the “no more wars” chants were met with equally strong chants of “USA USA.”

For Democrats, however, the bigger issue may not be about who is best qualified to lead a war abroad, but which candidate is most able to secure peace at home.