The newly announced deal between Iran and six world powers is “akin to declaring war on Israel and the Sunni Arabs,” and will be a huge problem for Hillary Clinton, according to GOP presidential candidate and Sen. Lindsey Graham, who promised to not uphold the deal if he is elected next year.

“My initial impression is that this deal is far worse than I ever dreamed it could be and will be a nightmare for the region, our national security and eventually the world at large,” Graham told me in an interview early Tuesday morning, just after Iran, China, France, Russia, Britain, the U.S. and Germany confirmed they had reached terms for a historic deal to limit Iran’s nuclear program in exchange for sanctions relief.

Graham, R-South Carolina, reacted harshly to many of the details about the deal that were emerging early Tuesday, including the news that the conventional arms embargo on Iran will be largely lifted and replaced by a limitation of Iranian arms imports and exports for five years. Reports also stated early Tuesday that limitations on Iran’s uranium enrichment program will begin to ease after eight years.

“If the initial reports regarding the details of this deal hold true, there’s no way as president of the United States I would honor this deal,” Graham said. “It’s incredibly dangerous for our national security, and it’s akin to declaring war on Sunni Arabs and Israel by the P5+1 because it ensures their primary antagonist Iran will become a nuclear power and allows them to rearm conventionally.”

Israeli Prime Minister Benjamin Netanyahu tweeted Tuesday that the deal was “a historic mistake.” Hillary Clinton has not yet reacted publicly; in the past she has expressed cautious optimism about the deal and said she was waiting to see the details.

“Hillary Clinton’s reaction to this deal is the first real test of her ability to be president and her judgment,” said Graham. “If she believes it’s a good idea to lift the arms embargo without first seeing a behavior change by the Iranians, then her judgment as commander in chief will be very much in question.”

He said President Obama put Democrats in an impossible situation: “He’s pitted Hillary Clinton and the Democratic Party against common sense and the security of the American people.”

Congress will have 60 days to review the deal, after it is submitted to them by the administration. After that, Congress will have the option of debating and passing a resolution of approval or a resolution of disapproval, or doing nothing and letting the deal stand. If Congress passes a resolution of disapproval, the president is likely to veto it, and then Congress will struggle to muster an override vote.

Many Democrats have kept their powder dry, awaiting the details of the final deal. They will likely be looking toward Clinton for guidance, as she is the favorite to be the party’s presidential nominee. The negotiations in Iran began while Clinton was secretary of state.

“She bears some responsibility for starting the process. The only question is, will she ratify the results?” said Graham.

In addition to the lifting of the embargo, Graham said lawmakers in both parties will be put off by the fact that the restrictions on Iranian enrichment expire over time. “There is no chance that this deal will be approved by Congress,” he said, predicting rejection by “an overwhelming super majority in both the House and the Senate.”

Graham also predicted that the deal would lead to an arms race in the Middle East and expanded hostilities between Shiite and Sunni Arabs all over the region. “If I had property in the Middle East, I would think about selling it after this deal.”

Josh Rogin, a Bloomberg View columnist, writes about national security and foreign affairs.