A look at the deal with Iran

After months of intense discussions, negotiators from the United States, Iran, and other leading international powers have reached an agreement to curb Iran’s nuclear program. Under the deal, most international sanctions against Iran will be lifted, and Tehran will dramatically scale back its enrichment activities for the next 15 years.

All is not quite done. Before the accord can be finalized, the US Congress will have its opportunity to weigh in. Still, even if Congress tries to block the agreement, President Obama can use his veto to ensure that it goes forward, transforming the United States and Iran from bitter foes to uncertain partners.

What is in the agreement?

The general contours of the deal are fairly straightforward. Iran wants an end to the sanctions that have crippled its economy. The United States, the United Kingdom, France, China, Germany, and Russia are trying to keep Iran from developing a nuclear weapon.

Negotiators built their agreement around this basic tradeoff. As Tehran dramatically scales back its nuclear program, the international community will lift its sanctions, which currently constrain Iran’s banks, preclude oil sales to the European Union, and limit a variety of other commercial and military activities.

According to the terms of the agreement, Iran’s ability to enrich uranium will be restricted for the next 15 years, and key Iranian facilities will be reorganized so as to limit their bomb-making abilities. Once Tehran demonstrates its compliance (a matter of weeks or months), most international sanctions will be lifted, though there are exceptions. The United States will maintain many of its own limits on companies wishing to do business with Iran, and Iran’s ability to buy and sell conventional weapons will be restricted for several more years.

What happens next?

An arrangement between legislators and the president gives Congress 60 days to vote on the accord. But while debate may be fierce — as opponents voice their concerns about whether the deal places enough limits on Tehran’s nuclear activities — it is unlikely to be decisive.

Even if the House or Senate votes against the deal, the president can use his veto, effectively blocking any interference from Congress. It is unlikely Congress could muster the votes needed to override a presidential veto in this case.

In the long-term, a future president could look less favorably on the current deal, and try in some way to stifle it. But even that might prove quite difficult. Effective sanctions generally require cooperation from lots of other countries, making it hard for the United States to act alone.

And the bigger issue may simply be facts on the ground. Assuming Iran has halted its nuclear activity, abrogating the agreement would be hard to justify.

What if Iran doesn’t comply?

To prevent Iran from feigning compliance, while still pursuing a secret nuclear program, the deal relies on a novel approach designed to quickly reinstate sanctions.

Should inspectors from the International Atomic Energy Agency uncover evidence of cheating, it could refer the issue to an eight-member panel of major powers, which includes Britain, China, France, Germany, Russia, the United States, the European Union, and Iran. And a simple majority vote from that panel would restore sanctions.

If you look over that list, you’ll see that together the United States and Europe control a majority of votes, meaning new sanctions couldn’t be blocked by opposition from China, Russia, and Iran.

What are the alternatives to this deal?

If the United States walks away from this deal, Iran would be free to expand its nuclear program and develop a weapon. Assuming the US wants to keep that from happening, it would need to do something else, and there aren’t all that many options:

■  Expand sanctions. The sanctions against Iran imposed by the United States and other countries have had a devastating impact on Iran’s economy, and broader sanctions might be even more crippling. But Iran has built much of its nuclear program while enduring those sanctions, and it could continue that process.

■  Attack Iran’s nuclear facilities. In the early 1980s, Israel successfully bombed a nuclear facility in Iraq. More recently, the Stuxnet computer virus wreaked havoc with Iran’s centrifuges. But given the way Iran’s nuclear program is organized (and defended), fully destroying it would be extremely difficult, and potentially impossible. And that’s without considering the possibility that it could set off a cycle of retaliation and escalation.

■  War to force regime-change in Iran. The rise of the Islamic State and the current chaos in Iraq don’t exactly reflect well on prior efforts to manage regime change in the Middle East.

Each of these alternatives carries its own substantial risks, which is one reason negotiators have persisted in their quest for a workable deal.

Might the US-Iran deal have unintended consequences?

It very well might. For decades, US policy in the Middle East has been organized around its mistrust of Iran. If this deal betokens a new, more constructive relationship between those two long-time rivals, it could upend other relationships.

Israeli Prime Minister Benjamin Netanyahu has already called the agreement a “historic mistake for the world,” complicating the vital, though increasingly strained relationship between the United States and Israel. And it’s possible that the deal might drive Saudi Arabia to pursue its own nuclear program as a way to counterbalance an unleashed Iran.

Then again, the United States has a long history of building trust with former enemies, whether it is Nixon in China, Reagan’s summits with Gorbachev, or our 19th-century reconciliation with the British crown. A nuclear deal with Iran can be understood in the same terms, as an attempt to replace hostility with diplomacy.