What is the Alternative to an Iran Deal?

Is there a millitary option? Former Defense Secretary Robert Gates:

The results of an American or Israeli military strike on Iran could, in my view, prove catastrophic, haunting us for generations in that part of the world.

Former Israeli spy chief Meir Dagan:

Attacking Iran would mean regional war, and in that case you would have given Iran the best possible reason to continue the nuclear program. . . . The regional challenge that Israel would face would be impossible.

Former Bush administration CIA director Michael Hayden:

When we talked about this in the government, the consensus was that [attacking Iran] would guarantee that which we are trying to prevent — an Iran that will spare nothing to build a nuclear weapon and that would build it in secret.

For a thorough look at what an attack would mean, the best thing I know is still the Atlantic's wargame exercise from 2004, which concluded that the U.S. has "no military option."

Ratcheting up the sanctions? To have any impact, sanctions can't just be a U.S. program, and our allies (let alone China and Russia) are not interesting in continuing them:

If U.S. officials reject a deal, Iran’s historic trading partners will not economically injure themselves indefinitely. Sanctions, declared Britain’s ambassador to the United States in May, have already reached “the high-water mark,” noting that “you would probably see more sanctions erosion” if nuclear talks fail. Germany’s ambassador added that, “If diplomacy fails, then the sanctions regime might unravel.”

So what?

I am no nuclear non-proliferation expert, so I can't really judge the content of the deal. But people who reject it out of hand ought to be thinking hard about what that might mean.