"But the story of how a president who rarely changes his mind did so in this case — after refusing similar proposals on Iran four years ago — illustrates the changed dynamic between the State Department and the White House in Mr. Bush's second term. When Colin L. Powell was secretary of state, the two buildings often seemed at war. But 18 months after Ms. Rice took over, her relationship with Mr. Bush has led to policies that one former adviser to Ms. Rice and Mr. Bush said "he never would have allowed Colin to pursue."
It is unclear how much dissent, if any, surrounded the decision, which appears to have been driven largely by the president, Ms. Rice and Mr. Hadley, with other senior national security officials playing a more remote role. Both White House and State Department officials say Vice President Dick Cheney, long an opponent of proposals to engage Iran, agreed to this experiment. But it is unclear whether he is an enthusiast, or simply expects Iran to reject suspending enrichment — clearing the way to sanctions that could test the Iranian government's ability to survive."
Like I said, there was no reason not to respond, even Cheney could see that (even if he just wants to "frame" Iran the way we tried to do Iraq). Nice to see W showing some flexibility lately... ah, the power of women.