Sparks quickly flew out of the gate Tuesday night during CBS News' vice presidential debate between Sen. J.D. Vance of Ohio and Minnesota Gov. Tim Walz.
When asked about Iran's nuclear capabilities, Walz said, "Iran is closer to a nuclear weapon than they were before because of [former President] Donald Trump's fickle leadership.
"And when Iran shot down an American aircraft in international airspace, Donald Trump tweeted, because that's the standard diplomacy of Donald Trump," he said.
Vance quickly shot back, arguing that diplomacy is not a dirty word.
"You yourself just said Iran is as close to a nuclear weapon today as they have ever been and, Gov. Walz, you blamed Donald Trump. Who has been the vice president for the last 3 1/2 years? And the answer is your running mate, not mine," he said.
Vance argued Trump has made the world more secure with diplomacy through strength.
"I'm 40 years old. When was the last time that an American president didn't have a major conflict break out? The only answer is during the four years that Donald Trump was president," he said.
With just weeks to go before the election, the two have been cutting a swath across the country in an attempt to secure key voters in hotly contested swing states.
Vance worked with Rep. Tom Emmer, R-Minn., on debate prep, while Walz did the same with Transportation Secretary Pete Buttigieg as his counterpart playing Vance.