President Trump announced Tuesday that the U.S. was withdrawing from the nuclear agreement between Iran and world powers, and that it would reinstate the punitive sanctions suspended under the 2015 accord.

The sanctions cover a range of of industries – from transportation and petroleum to insurance and finance – and will gradually come back into force over next six months.

It is not clear whether Mr. Trump’s decision will lead to a collapse of the agreement, which involves Iran and five other countries.

U.S. sanctions Iran’s nuclear program Inspections E.U. sanctions

After Trump’s announcement

Mr. Trump said he would restore nuclear-related sanctions.

All restrictions remain in place.

For now, inspections will continue.

Sanctions remain suspended or terminated.

Under the deal

The United States unfroze billions of dollars of impounded Iranian funds held in foreign banks and ceased application of nuclear-related sanctions.

Iran’s ability to surreptitiously make nuclear weapons was eliminated or severely compromised.

International experts were allowed to monitor Iran’s uranium mines and mills and centrifuge production, helping provide what experts called verifiable assurances.

United Nations sanctions tied to Iran’s nuclear work were terminated, and the European Union ended an oil embargo.

Before the deal

The U.S. banned the import of Iranian goods and services, and virtually all trade and investment by Americans in Iran was prohibited.

Iran had the technical capability to become a nuclear-weapons state, experts say. By some reckonings, Iran needed only a few months to make the required bomb fuel.

Some monitoring was done because Iran is a signer of the Non-Proliferation Treaty, but the monitoring was far less intrusive than under the nuclear agreement.

Extensive international sanctions, including an oil embargo and limits on Iranian banking, helped isolate and weaken Iran’s economy.

U.S. sanctions

After Trump’s announcement

Mr. Trump said he would restore nuclear-related sanctions.

Under the deal

The United States unfroze billions of dollars of impounded Iranian funds held in foreign banks and ceased application of nuclear-related sanctions.

Before the deal

The U.S. banned the import of Iranian goods and services, and virtually all trade and investment by Americans in Iran was prohibited.

Iran’s nuclear program

After Trump’s announcement

All restrictions remain in place.

Under the deal

Iran’s ability to surreptitiously make nuclear weapons was eliminated or severely compromised.

Before the deal

Iran had the technical capability to become a nuclear-weapons state, experts say. By some reckonings, Iran needed only a few months to make the required bomb fuel.

Inspections

After Trump’s announcement

For now, inspections will continue.

Under the deal

International experts were allowed to monitor Iran’s uranium mines and mills and centrifuge production, helping provide what experts called verifiable assurances.

Before the deal

Some monitoring was done because Iran is a signer of the Non-Proliferation Treaty, but the monitoring was far less intrusive than under the nuclear agreement.

E.U. sanctions

After Trump’s announcement

Sanctions remain suspended or terminated.

Under the deal

United Nations sanctions tied to Iran’s nuclear work were terminated, and the European Union ended an oil embargo.

Before the deal

Extensive international sanctions, including an oil embargo and limits on Iranian banking, helped isolate and weaken Iran’s economy.

Reimposing sanctions

Mr. Trump’s decision to restore sanctions was effective immediately, and will affect a range of industries that were able to engage with Iran under the nuclear agreement. But the Treasury Department said it would give businesses and individuals time – either 90 days or 180 days – for an “orderly wind down of activities.”

In a 10-page guidance document, the Treasury said sanctions enforcement would begin Aug. 6 on activities that include Iran’s purchase of commercial aircraft and services, Iran’s exports of carpets and food to the United States, and Iran’s trade in dollars, precious metals, industrial software, sovereign debt and the automotive sector.

On Nov. 4, sanctions enforcement would begin on industries that include shipping, oil, petrochemicals, insurance, energy and specialized banking and financial services.

The sanctions’ effects will depend partly on how non-American businesses and foreign governments respond, and whether they decide to risk U.S. penalties.

The most vulnerable Iranian industry may be oil, said Farhad Alavi, managing partner of Akrivis Law Group, a Washington law firm that specializes in international trade. The old U.S. sanctions, he said, “caused a severe drop in Iran oil exports – it was selling oil under the table at a discount.”

The deal could survive

Making good on a campaign promise to exit the nuclear agreement, Mr. Trump described it as so weak and lopsided in Iran’s favor that it was “a great embarrassment to me as a citizen and to all citizens of the United States.”

He faulted it for allowing Iran to eventually resume enrichment of nuclear fuel and for what he described as its failure to limit Iran’s missile development and “other malign behavior, including its sinister activities in Syria, Yemen and other places all around the world.”

But the American withdrawal does not necessarily mean the Iran agreement collapses — at least not immediately. Britain, China, France, Germany and Russia are still parties to the agreement. If they all agree to maintain it, the effect of restored American sanctions may be softened.

Mr. Trump also held out the possibility of negotiating a new agreement with Iran, though its leaders have said that won’t happen.

If the deal collapses, Iran will presumably be free to restart thousands of centrifuges mothballed under the agreement. That would let it increase its uranium fuel supply – without the close monitoring of the International Atomic Energy Agency.

Iran has said it could restore its uranium-enriching capability quickly, which could put it closer to a weapons path. But that might put Iran at risk of economic isolation, at least by the European countries that agreed to the accord.

What nuclear capabilities did Iran have before the deal?

Iran had the technical capability to become a nuclear-weapons state, experts say.

According to U.S. intelligence agency assessments, the Iranians once operated a covert nuclear weapons development program that they discontinued in 2003.

While Iran has repeatedly asserted that its nuclear activities are for peaceful use only, it had amassed a stockpile of uranium that further refining could have turned into fuel for nuclear bombs.

By some reckonings, Iran needed only a few months to make the required bomb fuel. It would have needed considerably more time to make a reliable warhead for a missile to deliver such a weapon.

U

Pu

Uranium

Plutonium

Centrifuges

‘Breakout’ time

About 8,000 kilograms

Production capable

More than 19,000

Three months or less

The heavy-water nuclear reactor under construction at Arak was meant to generate electricity, but its spent fuel could have also been mined for plutonium, a potent bomb fuel.

Amount of time it would have taken Iran to produce enough bomb-grade material for a single nuclear weapon.

If the 3.5 percent (low-enriched) uranium had been further enriched to weapons-grade (90 percent or more), the stockpile would have been sufficient to fuel more than seven nuclear warheads.

The rapidly spinning machines were enriching uranium at two main facilities, Fordow and Natanz.

Uranium

U

About 8,000 kilograms

If the 3.5 percent (low-enriched) uranium had been further enriched to weapons-grade (90 percent or more), the stockpile would have been sufficient to fuel more than seven nuclear warheads.

Plutonium

Pu

Production capable

The heavy-water nuclear reactor under construction at Arak was meant to generate electricity, but its spent fuel could have also been mined for plutonium, a potent bomb fuel.

Centrifuges

More than 19,000

The rapidly spinning machines were enriching uranium at two main facilities, Fordow and Natanz.

‘Breakout’ time

Three months or less

Amount of time it would have taken Iran to produce enough bomb-grade material for a single nuclear weapon.

U

Pu

Uranium

Plutonium

Centrifuges

‘Breakout’ time

About 8,000 kilograms

Production capable

More than 19,000

Three months or less

The heavy-water nuclear reactor under construction at Arak was meant to generate electricity, but its spent fuel could have also been mined for plutonium, a potent bomb fuel.

Amount of time it would have taken Iran to produce enough bomb-grade material for a single nuclear weapon.

If the 3.5 percent (low-enriched) uranium had been further enriched to weapons-grade (90 percent or more), the stockpile would have been sufficient to fuel more than seven nuclear warheads.

The rapidly spinning machines were enriching uranium at two main facilities, Fordow and Natanz.

Iran’s nuclear capabilities at the time the agreement was reached reflected a longstanding effort by the country to harness nuclear power. It began well before the revolution that overthrew the American-backed shah in 1979.

Iran is a signer of the Treaty on the Non-Proliferation of Nuclear Weapons, requiring it to use nuclear energy exclusively for peaceful purposes.

Despite Iran’s repeated denials, questions began to intensify more than 15 years ago about whether it had worked clandestinely to develop nuclear weapon capabilities.

Led by the United States, Western powers sought to pressure Iran with economic sanctions to curb its steadily increasing capacity to enrich uranium and produce plutonium, the fuels of atomic weapons.

After years of off-again-on-again negotiations, an agreement was reached in 2015 between Iran and the major world powers – Britain, China, France, Germany, Russia and the United States. It was endorsed by the United Nations.

Here’s how the deal changed Iran’s nuclear program.

U

Pu

Uranium

Plutonium

Centrifuges

‘Breakout’ time

No more than 300 kilograms

Reduced weapons potential

Reduced by roughly two-thirds

At least one year

The Arak reactor was rendered inoperable. Its eventual replacement will reduce weapons-grade plutonium potential. Iran pledged to permanently export spent nuclear fuel.

Low-enriched uranium was reduced to less than one bomb’s worth, roughly a 95 percent reduction, for 15 years. Most of the excess was shipped to Russia.

Roughly 13,000 centrifuges were dismantled and stored under continuous monitoring by the International Atomic Energy Agency. Gradual restoration would start after 10 years.

Uranium

U

No more than 300 kilograms

Low-enriched uranium was reduced to less than one bomb’s worth, roughly a 95 percent reduction, for 15 years. Most of the excess was shipped to Russia.

Plutonium

Pu

Reduced weapons potential

The Arak reactor was rendered inoperable. Its eventual replacement will reduce weapons-grade plutonium potential. Iran pledged to permanently export spent nuclear fuel.

Centrifuges

Reduced by roughly two-thirds

Roughly 13,000 centrifuges were dismantled and stored under continuous monitoring by the International Atomic Energy Agency. Gradual restoration would start after 10 years.

‘Breakout’ time

At least one year

U

Pu

Uranium

Plutonium

Centrifuges

‘Breakout’ time

No more than 300 kilograms

Reduced weapons potential

Reduced by roughly two-thirds

At least one year

The Arak reactor was rendered inoperable. Its eventual replacement will reduce weapons-grade plutonium potential. Iran pledged to permanently export spent nuclear fuel.

Low-enriched uranium was reduced to less than one bomb’s worth, roughly a 95 percent reduction, for 15 years. Most of the excess was shipped to Russia.

Roughly 13,000 centrifuges were dismantled and stored under continuous monitoring by the International Atomic Energy Agency. Gradual restoration would start after 10 years.