Joe Biden wants to return to the nuclear agreement between Iran and the six major world powers. Would restoration of the nuclear deal be good for the United States -- and also for Israel, despite the opposition of its government?

Yes. The agreement does not cover other conflicts, and key provisions are for limited time periods. But the United States and Israel -- and everyone else including Iran's Arab neighbors -- are better off with the deal than without it. Consider the following basic facts:

1. There are two feasible paths to nuclear weapons: uranium enriched to the 90% level with the U-235 isotope, and plutonium. Both involve massive facilities that cannot be successfully hidden from modern technological surveillance. We know this because the Iranians tried and failed -- twice.

2. The key to preventing a nation from developing nuclear weapons lies, therefore, in blocking access to 90%-enriched uranium or plutonium.

3. Since Iran is a signatory of the Nuclear Non-Proliferation Treaty (NPT), all of its facilities capable of producing enriched uranium or plutonium are supervised by the International Atomic Energy Agency (IAEA).

4. Iran had produced enough uranium enriched to 3.67% to make several bombs, if this material had been further enriched to 90%. It had also produced some 20%-enriched uranium. Under the agreement, the latter was entirely removed and the former was reduced by 97%, under IAEA supervision.

5. An Iranian nuclear reactor under construction, which would have produced plutonium as a byproduct, was redesigned so that it will not produce any weapons-grade material, under IAEA supervision.

6. Iran had agreed to the IAEA Additional Protocol, which subjects its nuclear sites to constant and tighter inspection and permits challenge inspections of undeclared sites. But because the United States left the agreement, Iran just announced that it will no longer permit such inspection.

7. When specific limits of the agreement expire (in 10, 15, or 20 years), Iran is to be treated like any other non nuclear-weapons state in the NPT. In other words, production of enriched uranium or plutonium must still be justified by non-military needs, IAEA inspection would still be in place, and sanctions could still be reinstituted if other nations concluded that the intent was to develop weapons.

8. The only concession made by the six powers negotiating with Iran was to end sanctions related to the nuclear issue. Sanctions related to other issues remain in effect.

9. Sanctions on nuclear issues were effective in forcing Iran to the table because they enjoyed almost-universal support. Other issues such as Iran's ballistic missiles or its support of terrorism were not on the agenda, though the U.S. and other nations can sanction Iran on these questions.

10. Since the United States left the treaty, Iran has openly produced more enriched uranium than permitted by it. Under the limits of the agreement, Iran's break-out time -- the time required to produce a critical mass of enriched uranium if it were to break out of the agreement completely -- was about one year. With Iran's deviation from the agreement, this break-out time is now estimated at three-four months.

Clearly this has not improved U.S. or Israeli security. If the agreement is not restored, the likely alternative is not a better deal. The most likely alternative is war.