President Trump seemingly served notice Friday that the days are dwindling for Barack Obama’s Iran agreement. Although deal proponents also gained time to pursue “fixes,” this is a forlorn option. No fix will remedy the diplomatic Waterloo Mr. Obama negotiated. Democrats will reject anything that endangers his prized international contrivance, and the Europeans are more interested in trade with Tehran than a stronger agreement.

There is an even more fundamental obstacle: Iran. Negotiating with Congress and Europe will not modify the actual deal’s terms, which Iran (buttressed by Russia and China) has no interest in changing. Increased inspections, for example, is a nonstarter for Tehran. Mr. Obama gave the ayatollahs what they wanted; they will not give it back.

Most important, there is no evidence Iran’s intention to obtain deliverable nuclear weapons has wavered. None of the proposed “fixes” change this basic, unanswerable reality.

Spending the next 120 days negotiating with ourselves will leave the West mired in stasis. Mr. Trump correctly sees Mr. Obama’s deal as a massive strategic blunder, but his advisers have inexplicably persuaded him not to withdraw. Last fall, deciding whether to reimpose sanctions and decertify the deal under the Corker-Cardin legislation, the administration also opted to keep the door open to “fixes” — a punt on third down. Let’s hope Friday’s decision is not another punt.

The Iran agreement rests on inadequate knowledge and fundamentally flawed premises. Mr. Obama threw away any prospect of learning basic facts about Iran’s capabilities. Provisions for international inspection of suspected military-related nuclear facilities are utterly inadequate, and the U.S. is likely not even aware of all the locations. Little is known, at least publicly, about longstanding Iranian-North Korean cooperation on nuclear and ballistic-missile technology. It is foolish to play down Tehran’s threat because of Pyongyang’s provocations. They are two sides of the same coin.

Pictured: The perimeter defenses of the underground nuclear fuel enrichment plant in Natanz, Iran. (Image source: Hamed Saber/Wikimedia Commons)

Some proponents of “strengthening” the deal propose to eliminate its sunset provisions. That would achieve nothing. Tehran’s nuclear menace, especially given the Pyongyang connection, is here now, not 10 years away. One bizarre idea is amending the Corker-Cardin law to avoid the certification headache every 90 days. Tehran would endorse this proposal, but it is like taking aspirin to relieve the pain of a sucking chest wound.

Putting lipstick on this deal will not fix it. Why would Democrats facilitate Mr. Trump’s inclinations to withdraw from the deal entirely? If he’s going to abrogate it, why be complicit by adding new conditions that Iran will fail to meet? Sen. Ben. Cardin has correctly observed the president already has all the authority he needs.

To avoid that danger, some senators have suggested restricting the president’s ability to withdraw from the deal without congressional approval. This folly is so obviously unconstitutional it fully warrants a Trump veto.

Europeans are collectively following a Micawberesque approach of counting their revenues and hoping for the best. They rightly fear that if U.S. intellectual property again falls under sanctions, they will be barred from selling Tehran products containing that technology. U.S. withdrawal is therefore critical to breaking Europe’s addiction to Iranian commercial prospects.

U.K. Foreign Secretary Boris Johnson has reasonably asked what the alternative policy would be. Iran’s recent widespread demonstrations against the ayatollahs provide the answer. Tehran’s rulers are far more unpopular than previously believed. Like many seemingly impregnable authoritarian regimes, the facade belies the reality. Iran’s opposition needs external support, material as well as rhetorical, to continue its momentum. It would be tragic not to torque up the economic pressure by reactivating all sanctions now under waiver, and adding more.

America’s declared policy should be ending Iran’s 1979 Islamic Revolution before its 40th anniversary. Arab states would remain silent, but they would welcome this approach and might even help finance it. Israel can also remain silent but pressure Iran’s forces, as well as its clients, in Lebanon and Syria, to maximize the stress on Iran’s security assets.

Recognizing a new Iranian regime in 2019 would reverse the shame of once seeing our diplomats held hostage for 444 days. The former hostages can cut the ribbon to open the new U.S. Embassy in Tehran.