Presidential hopeful Bernie Sanders sought Thursday to sharply contrast his foreign policy judgment with that of Democratic front-runner Hillary Clinton, saying that the “ill-conceived” invasion of Iraq that she supported led to the far-reaching destabilization of the Middle East.

“I’m not running to pursue reckless adventures abroad, but to rebuild America’s strength at home,” the Vermont senator said. “I will never hesitate to defend this nation, but I will never send our sons and daughters to a war under false pretense.”

Sanders’s remark came toward the end of a long address on another topic — the philosophy of “democratic socialism” that has guided his political career — but the timing of his barb appeared deliberate.

Hours earlier, Clinton gave a major address in New York in which she called for the United States to lead a global fight to exterminate the Islamic State terror network in the wake of the Paris attacks. She also set out a far more activist agenda to confront the militants than the Obama administration has mounted.

Sen. Bernie Sanders (I-Vt.), spoke about climate change, the Islamic State, racism and his vision for the country at Georgetown University on Nov. 19. Here are the key moments. (Sarah Parnass/The Washington Post)

In his remarks at Georgetown University, Sanders said the United States should play a role in the destruction of the Islamic State, but he said the primary responsibility belongs to Muslim nations.

“The fight against ISIS is a struggle for the soul of Islam, and countering violent extremism and destroying ISIS must be done primarily by Muslim nations,” Sanders said.

He specifically called out the wealthy countries in the Middle East, saying “wealthy and powerful Muslim nations in the region can no longer sit on the sidelines and expect the United States — our young men and women and our taxpayers — to do their work for them.”

Sanders decried reports that Qatar is spending $200 billion to host soccer’s World Cup in 2022, but is willing to spend “very little to fight against ISIS.”

Thursday’s speech, in which Sanders did not mention the more hawkish Clinton by name, was not the first time he has highlighted her vote on Iraq in 2002 as a senator from New York — which she has since said was a mistake.

It has become a key argument for Sanders against a candidate who is the former secretary of state and has greater foreign policy experience. Sanders was a member of the House of Representatives at the time of the vote.

"If Donald Trump and others refer to Latinos and people from Mexico as criminals and rapists, if they want to open that door, our job is to shut that door and shut it tight," Sen. Bernie Sanders (I-Vt.) said at Georgetown University Nov. 19. (AP)

Sanders devoted the bulk of his remarks Thursday to an explanation of what “democratic socialism” is — and isn’t — in his view. The term he uses to describe his politics has become a major topic of conversation, and drawn some derision, as he seeks the presidency.

“The next time you hear me attacked as a socialist — like tomorrow — remember this,” Sanders told an audience composed largely of college students. “I don’t believe government should take over the grocery store down the street or own the means of production, but I do believe that the middle class and the working families of this country . . . deserve a decent standard of living and that their incomes should go up, not down.”

Sanders traced his vision for the country back to Franklin Delano Roosevelt, citing his efforts in the late 1930s to implement initiatives including Social Security, a minimum wage and a 40-hour work week.

Those efforts were derided as “socialist” at the time, Sanders said, and yet “all of these programs and many more have become the fabric of our nation and, in fact, the foundation of the middle class.”

Sanders said the initiatives he is pushing as a presidential candidate are intended to stem a growing tide of income and wealthy inequality in a nation “in which billionaires compete as to the size of their super-yachts, while children in America go hungry and veterans . . . sleep out on the streets.”

“My view of democratic socialism builds on the success of many other countries around the world who have done a far better job than we have in protecting the needs of their working families, their elderly citizens, their children and their sick and the poor,” he said.

Sanders cited his plans to make public college tuition free, to provide universal health care through a “Medicare for all” system, and to raise the minimum wage to $15 per hour.

Clinton has proposed addressing many of the same issues that Sanders cited, but she generally advocates programs that are less ambitious and less costly.

Sanders also made clear Thursday, as he has on the campaign trail, that the wealthy and corporations could expect to pay more in taxes under his administration.

“Democratic socialism means, that in a democratic, civilized society the wealthiest people and the largest corporations must pay their fair share of taxes,” Sanders said. “Yes. innovation, entrepreneurship and business success should be rewarded. But greed for the sake of greed is not something that public policy should support.”