Last week I noted that I consider the agreement between the group of countries led by the United States and Iran restraining Iran’s nuclear program to be a very significant accomplishment that deserves praise as a major positive accomplishment.

This judgment is based on my invocation of a very important principle that guided all of my decisions in my public life and continues to be my guide as a private citizen. It was articulated by a man whom I think of as an important 20th century philosopher: Henny Youngman, the king of the one-liners.

One of his jokes offers a profound guide to the process by which important issues should be decided. “How’s your wife?” was the question and the answer was, “Compared to what?”

I rarely found myself during my career in a situation where I could come up with a solution that was wholly satisfactory to a problem. By definition, problems are situations that are far from ideal, and decision-making involves figuring out how to maximize the benefits and minimize the risks that are inherent in a difficult reality.

So I begin my defense of the Iran agreement by asking those who oppose it to tell me what achievable alternative they would compare it to.

One answer is a fantasy – namely that they would have preferred a better agreement. If we were in a world in which we could make whatever we wanted to happen a reality, I would agree. But the fact is that what was achieved was clearly the best agreement that could have been reached. One strong piece of evidence in favor of this conclusion is the continuity that exists on this issue between the Bush and Obama administrations. If it had been possible simply to get Iran to agree to drop all nuclear efforts, why would President Bush not have achieved this? He had all the tools available to President Obama. I say this because one of those weapons – the one that I believed proved the most effective in this success that Obama did achieve – was use of economic sanctions, and I am proud to claim significant authorship of this.

It was during my chairmanship of the House Financial Services Committee during the Bush administration that we first adopted a strong Iran sanctions bill, with the main drafter of the legislation being my special council and longtime close friend Jim Segel, himself a former president of the Jewish Community Relations Council and as strong a critic of Iranian nuclear intentions as existed.

But for all its efforts, the Bush administration achieved no retardation at all. The argument from Prime Minister Benjamin Netanyahu and others that “a better deal” was possible ignores their own views of the Iranian regime. These critics describe the Iranian regime as a wholly intransigent one, bent on regional domination and unwilling to show any accommodation. Given this depiction, what basis do they have for saying that somehow Iran could have been persuaded to concede even more than they did?

In fact, there were only two other possible outcomes from these negotiations. One was no deal at all. The other, which I believe many, including Netanyahu, really support was a war in which American would take the lead.

Neither of these seemed to me preferable.

The argument for no deal at all is that what Obama achieved will do little to stop Iran from developing nuclear weapons, and that in fact by agreeing with them we gave them legitimacy and somehow signaled a willingness to allow them to expand their influence in the region.

To the contrary, the deal does represent significant concessions from Iran, although, again, not what I would have preferred if I had a magic wand. First, it should not be ignored that the basis for this whole deal was an Iranian agreement that they should not have nuclear weapons. Only one other power with nuclear capabilities – Libya – has made such a concession. And it is a significant one.

Iran is a nation that is engaged in a worldwide effort to improve its standing and to convince people in the region and elsewhere that they are a responsible nation; having agreed that they should not have nuclear weapons, if they were to break that pledge, they would be opening themselves to a degree of criticism that they clearly wish to avoid. If their intention were simply to go ahead with nuclear development, why would they have repudiated the notion that they were entitled to such a status? The answer is that Obama very effectively used the sanction legislation that we had passed, formed a coalition with other nations and generated enough pressure on Iran to force them to say something they clearly would rather not have said.

And it is not simply a declaration by Iran that they will not pursue nuclear weapons that was achieved. The agreement contains significant changes in Iranian nuclear policy, reducing its ability to develop weapons, even if the Iranians decide to risk the global obloquy of breaking their pledge. I am not an expert in these matters – a status I share with many who are claiming that the deal had no teeth. Energy Secretary Ernest Moniz, an MIT nuclear physicist, carries great weight with me in his declaration that the provisions of the agreement have real meaning.

Given the nature of relations between Iran and the western nations with which it was negotiating and the insistence on its sovereignty that Iran shares with every other nation, its agreement to reduce its physical capacity – and to extend the time by a significant amount which would have to elapse before it develops weapons – was a major achievement. That is especially the case because all Iran gets in return is a suspension of sanctions. I say suspension because these sanctions were unilaterally imposed by us and other nations and can easily be reimposed should the Iranians break the deal in any way. There is one possible obstacle. An acceptable deal requires significant international inspection of what happens within that country, an intrusion into their internal affairs that is, frankly, not only more than the Bush administration was ever able to achieve, but more than many thought might be possible at the outset of these negotiations. But this must apply throughout Iran. The recent effort by Ayatollah Ali Khamenei to limit the inspection of military sites must be rejected if the deal is to survive.

The other alternative, which many of the agreement’s critics prefer, is an attack on Iran, led by our country. The first thing that must be said about this is that every expert agrees that short of an American occupation of Iran, an approach that would make the American troubles in Iraq seem like the Easter parade, nothing would prevent an Iranian nuclear capacity. It is too big a country, with too many places to hide activities, for any one-time or even two-time physical assault to prevent nuclear weapons, and in fact, such an attack would guarantee that the Iranians would develop their capacity in a physically secure way as quickly as possible. The war in Iraq that President Bush initiated was the single biggest disaster any American president ever caused. War with Iran would be far worse.

What we have is an agreement achieved by Obama, beyond what Bush was ever even close to achieving, that consists of Iran acknowledging that it would be wrong for it to develop nuclear weapons, retards Iranian nuclear efforts and gives us a longer period than we would otherwise have had to react if they do begin to develop weapons.

Compared with that, neither war nor total absence of an agreement seems to be desirable.

Barney Frank is a retired congressman and the author of landmark legislation. He divides his time between Maine and Massachusetts.

Twitter: BarneyFrank