09/06/2015 16:57 EDT | Updated 09/06/2016 01:12 EDT

Old Bush-era rivals tangle again, this time on Iran, and Powell's beating Cheney

An old rivalry within the George W. Bush cabinet over the invasion of Iraq has resurfaced, this time over next-door Iran — and this time it's headed for a different result.

The longrunning foreign-policy feud between Dick Cheney and Colin Powell has re-emerged over the historic, controversial Iran nuclear deal more than a decade after they tangled over Iraq.

The old foes who battled in the backrooms of the Bush administration came out on opposite sides of the Iran deal in duelling appearances on Sunday talk shows.

Powell endorsed it and the latest developments should give him cheer that his preferred solution is carrying sway, as congressional support trends toward the deal and a victory for President Barack Obama.

"I think it is a good deal. I've studied very carefully the outline of the deal and what's in that deal," Bush's former secretary of state told NBC's Meet The Press.  

"And I've also carefully looked at the opposition to the deal. My judgment after balancing those two sets of information is it's a pretty good deal."

The arrangement would see Iran promise to suspend efforts toward a bomb, agree to relinquish much of its nuclear capacity, and submit to inspections in exchange for economic benefits — a loosening of some international sanctions and the ability to export oil.

Opponents of the deal have three main criticisms: that a richer Iran will transfer cash to listed terrorist groups like Hezbollah and further destabilize the Middle East; that the inspections system is too weak; and that once it expires in 15 years Iran could resume its nuclear ambitions and threaten Israel.

Those opponents may have had reason for optimism until recently. Polls suggest most Americans oppose the deal, an expensive anti-deal ad campaign began pounding the airwaves, and some prominent Democrats including the party's next Senate leader Chuck Schumer came out against it.

But the tide has turned. 

Obama already has enough votes to veto of an anti-deal bill in Congress. The skeptical Saudis came out in favour of the deal this week. The British government has organized a trade mission to Iran. And now Obama's congressional allies are striving for a few more votes that would make a veto unnecessary.

On Sunday, Powell said he was amazed Iran agreed to a near-total-elimination of its uranium stockpiles, and noted that the deal would reduce centrifuges by three-quarters and see concrete poured into the core vessel at the Arak facility.

On another network, his old nemesis was blasting the agreement.

Cheney, the former vice-president, has compared Obama to the Nazi-appeaser Neville Chamberlain, the British prime minister who attempted to make peace with Adolf Hitler.

He told Fox News that Iran would gain dominance in its region.

"I think it's a big deal," Cheney said. 

"A major, major defeat in my mind, in terms of our position in the region."

The Fox interviewer challenged him. Chris Wallace retorted that Iran's known centrifuges had leaped from zero to more than 5,000 during the Bush years, without a deal: "Didn't you leave ... President Obama with a mess?"

Those competing appearances Sunday were reminiscent of a dispute that played out more discreetly during both U.S.-Iraq wars.

Some colleagues felt Powell was trying to undermine the 2003 invasion. He never actually expressed opposition to it, and in fact presented some of the administration's now-disrcredited evidence to the United Nations.

But he annoyed Cheney by pushing for UN authorization; by repeatedly voicing the things that could go wrong; and by letting word of his skepticism spread throughout Washington.

In his memoir, Cheney said he wanted Powell gone as secretary of state: "I was particularly disappointed in the way he handled policy differences... It was as though he thought the proper way to express his views was by criticizing administration policy to people outside the government."

The rivalry goes back to the first Gulf War, when Powell got the better of the then-secretary of defence — Cheney. At the time, the dispute was whether to continue into Baghdad.

Powell was more dovish then, too. On Sunday, he repeated his now-famous warning about what would happen should the U.S. take out Saddam Hussein.

"My view was," Powell said Sunday, "if you break it you're going to own it."

Alexander Panetta, The Canadian Press