Mr. Obama essentially surrendered in the face of similar tactics at the end of 2010, extending low taxes on the rich for two more years. He made significant concessions again in 2011, when Republicans threatened to create financial chaos by refusing to raise the debt ceiling. And the current potential crisis is the legacy of those past concessions.

Well, this has to stop — unless we want hostage-taking, the threat of making the nation ungovernable, to become a standard part of our political process.

So what should he do? Just say no, and go over the cliff if necessary.

It’s worth pointing out that the fiscal cliff isn’t really a cliff. It’s not like the debt-ceiling confrontation, where terrible things might well have happened right away if the deadline had been missed. This time, nothing very bad will happen to the economy if agreement isn’t reached until a few weeks or even a few months into 2013. So there’s time to bargain.

More important, however, is the point that a stalemate would hurt Republican backers, corporate donors in particular, every bit as much as it hurt the rest of the country. As the risk of severe economic damage grew, Republicans would face intense pressure to cut a deal after all.

Meanwhile, the president is in a far stronger position than in previous confrontations. I don’t place much stock in talk of “mandates,” but Mr. Obama did win re-election with a populist campaign, so he can plausibly claim that Republicans are defying the will of the American people. And he just won his big election and is, therefore, far better placed than before to weather any political blowback from economic troubles — especially when it would be so obvious that these troubles were being deliberately inflicted by the G.O.P. in a last-ditch attempt to defend the privileges of the 1 percent.

Most of all, standing up to hostage-taking is the right thing to do for the health of America’s political system.

So stand your ground, Mr. President, and don’t give in to threats. No deal is better than a bad deal.