TEHRAN, Young Journalists Club (YJC) - Mark Milley also said the United States should keep a "modest number" of forces in Iraq and Syria for now to maintain stability.
Milley assured the Senate Armed Services Committee that he will give his candid advice to President Donald Trump regardless of any potential consequences to himself.
"We've buried soldiers. Arlington is full of our comrades. We understand absolutely full well the hazards of our chosen profession," Milley said, in response to questions from Sen. Angus King, I-Maine, about whether he would be willing to tell Trump that he thought the president was wrong on any issue. "We know what this is about and we are not going to be intimidated into making stupid decisions."
The 61-year-old Milley, who is Trump's pick to replace Gen. Joseph Dunford, said "no one, ever" would intimidate him.
He received a friendly reception from the committee and appears headed for an easy confirmation.
Milley is combat-hardened veteran of multiple tours in the Iraq and Afghanistan wars, including as a senior commander.
If confirmed, Milley, who has been serving as the chief of staff of the Army since August 2015, would take over as Joint Chiefs chairman by the end of September.
Trump has pressed for withdrawing U.S. troops from Syria and Afghanistan. But so far there have been few reductions, reflecting military commanders' urgings to maintain the status quo for now.
The U.S. peace envoy to Afghanistan, Zamal Khalilzad, has said the latest round of talks with the Taliban made substantive progress. Secretary of State Mike Pompeo said last month that Washington is hopeful a peace agreement to bring an end to the war can be reached before Sept. 1.
Milley told senators that American's participation in the war would come to an end "when our interests are met," and that includes a negotiated settlement with the Taliban.
"It is slow, it's painful, it's hard," he said.