Conservative foreign policy hawks are blasting the Obama administration's preliminary nuclear deal with Iran as nothing more than a "series of cascading concessions" that have sold America and its allies in the Middle East short. These conservatives are probably right that the administration could have negotiated a better deal. Still, contrary to their claims, a bad deal is better than no deal. That's because all the other options — maintaining sanctions or launching military strikes — would be less effective in curbing Iran's nuclear ambitions.

There are many details of the deal that have yet to be finalized, and there is a non-trivial chance that the whole thing will collapse. Iranian President Hassan Rouhani declared this week that he won't go for a deal that lifts the sanctions gradually rather than fully and right off the bat.

But here's what we know: As the deal currently stands, for the next 10 to 15 years, Iran will have to give up 14,000 of its 20,000 centrifuges, keeping only the first generation kind that can't be used to enrich weapons grade material. Iran will have to abandon 97 percent of its enriched uranium stockpile by either shipping it out or neutralizing it to its natural state (as opposed to simply oxidizing it, a process that's easily reversed). Iran will have to fit its Arak heavy reactor, a major proliferation threat, with a central vessel or calandria capable of holding only 1 kilogram of plutonium rather than the current 10 kilograms. Iran will have to use its Fordo facility, built in secrecy, only for peaceful nuclear purposes. Iran will also have to ratify the Additional Protocol, an intrusive inspections regime that will allow inspectors unfettered access at a day's notice to any site they deem suspicious.

All of this is expected to increase Iran's "breakout time" — the time needed to acquire enough fissile material for a bomb — from about a few months to a year. The idea is that a year is long enough for the international community to do something.

Saudi Arabia and Israel argue that the Obama administration did not drive a hard enough bargain. Even France, America's negotiating partner, is backing their claims.

They point out that U.S. negotiators led by Secretary of State John Kerry confused Iranian posturing for sincere concern. The American team accepted Iran's claim that the nuclear program was its "shot at the moon" and conceded Tehran's "right" to maintain its nuclear facilities — instead of pushing for their dismemberment. "The haggling had scarcely begun and already the merchant profited," laments Michael Oren, Israel's former ambassador to America.

That Kerry behaved like an innocent abroad is hardly implausible. However, does this mean that Congress should now "kill the deal" and redouble its efforts to keep in place the current sanctions regime as Israeli Prime Minister Benjamin Netanyahu, The Weekly Standard, and other hawks are demanding?

No, because that's not even an option anymore. Regardless of whether the deal stands or falls, the sanctions are not long for this world.

The sanctions have already succeeded in bringing Iran to the table by triggering a major recession, shortages, and inflation. (The sanctions included a boycott of Iran's oil exports and also limited Iran's access to refined oil, while barring international banks from doing business with Iran.)

However, because the sanctions were not exactly costless for the countries imposing them, they were a tough sell that required years of diplomacy. Particularly reluctant to hop on board were Russia and China, who had to give up lucrative deals to build Iran's refinery capacity and infrastructure. Indeed, this duo was only shamed into committing to the sanctions regime after 2006, when the U.N. Security Council issued six resolutions condemning Iran's nuclear activity in violation of its obligations under the Nuclear Non-Proliferation Treaty.

Given this backdrop, there was never any chance that the international will for a foolproof sanctions regime would last indefinitely. The sanctions were meant to create a window for negotiations and, regardless of what America does now, that window will slam shut soon. This means that if America walks away from the deal, Iran will slowly resume normal trade ties with much of the world — but without having to accept any curbs on its nuclear program.

And if a renewed sanctions regime is unrealistic, Sen. Tom Cotton's (R-Ark.) Wednesday call for military strikes is downright daft.

Cotton insists that degrading Iran's nuclear capacity won't require a prolonged military operation — just a few days of sustained aerial strikes of the kind that President Bill Clinton used in the 1999 Desert Fox Operation against Iraq's weapons of mass destruction.

However, what Cotton is forgetting is that Iraq's WMD facilities weren't buried under 200 feet of rock — Iran's Fordo facility is. Indeed, Tehran has gone to great lengths to shield its facilities against precisely such an attack. At the very minimum, notes James Kitfield of the Nuclear Threat Initiative, any significant erosion of Iran's nuclear infrastructure would require weeks, not days, of bombardment. Even if a war-weary American public resigned itself to such a campaign, it would at best set Iran's nuclear program back by four years, according to a 2012 report signed by multiple generals.

Military strikes might also generate negative unintended consequences. Iran could lash out against Israel or American facilities in the area — either directly or through proxies like Hezbollah, the report warns, destabilizing an already unstable region even further. The strikes could even trigger an all-out war — hardly what a region that is already dealing with multiple civil wars and the rise of barbaric outfits such as ISIS needs.

More to the point, military strikes might increase Iran's resolve for a nuclear weapon on the theory that America is far less inclined to mess with countries that have one (think Pakistan and China).

The administration might have squandered precious leverage in its negotiations. However, even the deal that it has obtained through its ham-handed efforts is a far cleaner — and surer — way to slow Iran's march toward a nuclear bomb. Obama didn't get the moon — but the deal won't produce the end of the world either, which is more than one can say for the options foreign policy hawks have put on the table.