South Carolina Sen. Lindsey Graham and Texas Sen. Ted Cruz, both seeking the 2016 GOP presidential nomination, sharply criticized the officials over the deal recently struck between the U.S. and Iran as well as their stance on Iranian behavior.
Graham asked Defense Secretary Ashton Carter, one of the witnesses, whether the Iranian supreme leader's religious views "compel him over time to destroy Israel and attack America?"
When Carter said, "I don't know. I don't know the man," Graham responded: "Let me tell you, I do. I know the man. I know what he wants. And if you don't know that, this is not a good deal."
At another point, Cruz interrogated Carter about the money that is likely to go to Iran after sanctions are lifted and the economy there begins to recover.
"Do you have any doubt whatsoever if an excess of $100 billion goes to Iran, that some of that money will go to Jihadists who will use it to murder Americans?" Cruz asked him.
"I can't say that," Carter replied. "I can say that their malign activities, about which we're extremely concerned, are quite well-funded today and it's those malign activities (and) the rest of their conduct that makes it so important that they not also have a nuclear weapon."
Additional U.N. sanctions on Iran's missile program will also be lifted several years into the nuclear deal -- despite strong words from Joint Chiefs of Staff Chairman Gen. Martin Dempsey before the deal was complete on July 14 discouraging such a provision.
Republican New Hampshire Sen. Kelly Ayotte questioned Dempsey about his statement at Wednesday's hearing.
"You said under no circumstances should we relieve the pressure on Iran on this issue, so was it your military recommendation that we not agree to the lifting of those sanctions?" she said.
"Yes, and I used the phrase 'as long as possible,'" Dempsey said, noting that the negotiations were ongoing at that time. "But yes, that was my military recommendation."
Another Republican senator, Mike Lee of Utah, challenged Secretary of State John Kerry on why the U.S. didn't put down stronger ground rules for Iranian behavior before entering talks.
"Why on earth didn't we insist on a condition, a precedent to getting any deal at all, that Iran, for the love of God, cease and desist from its terrorist ambitions? Cease and desist from making comments like it wants to wipe Israel of the map?" he asked.
"It would be great and ideal if one could negotiate that," Kerry told him. "We felt that we had to keep this targeted on the greatest threat of all, which you just defined, which is them having a nuclear weapon."