ISLAMABAD — US negotiators arrive in Pakistan on Monday carrying what Iranian officials privately call "maximalist demands" that have already torpedoed three rounds of indirect talks since March.

The Americans want Iran's nuclear program rolled back to 2015 levels within 90 days. Complete withdrawal from the Strait of Hormuz. And Mojtaba Khamenei, Iran's new Supreme Leader, to publicly renounce his father's legacy of resistance to Washington.

Iran's response? Not happening.

The American offer

The US package includes $50 billion in frozen Iranian assets, removal of banking sanctions, and a guarantee that Israel will not strike Iranian nuclear facilities for 18 months. Trump administration officials say it's the most generous offer Iran will see.

"We're not negotiating from weakness here," said Deputy Secretary of State Brian Hook, who will lead the US delegation. "Iran's economy is hemorrhaging. Their proxies are gone. This is their off-ramp."

But Iranian negotiators who spoke on condition of anonymity said the timeline is impossible. Rolling back uranium enrichment from 84% to 3.67% — the level permitted under the 2015 nuclear deal — would take at least six months even with full cooperation.

"They want us to dismantle in 90 days what took us eight years to build," said one Iranian official. "It's not technically feasible even if we wanted to do it."

The Hormuz stranglehold

Iran's closure of the Strait of Hormuz on April 12 remains the biggest sticking point. The waterway carries 21% of global petroleum liquids, and its shutdown has pushed Brent crude to $127 per barrel — a 2026 high.

Iranian Revolutionary Guard commanders say reopening the strait would signal weakness after seven months of war with Israel. The IRGC has mined key shipping channels and deployed anti-ship missiles along both coastlines.

"Hormuz is our trump card," said IRGC naval commander Admiral Alireza Tangsiri in comments published by Tasnim news agency. "Why would we give it up for promises?"

Pakistan's foreign ministry confirmed that talks will begin Tuesday at the Serena Hotel in Islamabad. But Pakistani mediators are already lowering expectations.

"The gaps are significant," said Foreign Minister Bilawal Bhutto-Zardari. "Both sides need to show flexibility that frankly we haven't seen yet."

Tehran's new power structure

The death of Ali Khamenei in February airstrikes fundamentally altered Iran's decision-making structure. His son Mojtaba, 57, lacks his father's revolutionary credentials and faces pressure from hardliners who want to escalate the conflict.

Iranian parliament speaker Mohammad Bagher Ghalibaf — who survived the Tehran strikes — has emerged as the voice of the military establishment. He opposes any deal that doesn't include Israeli withdrawal from occupied Iranian territory.

"We will not negotiate under the gun," Ghalibaf told lawmakers Thursday. "Any agreement must address the root causes of this conflict, not just its symptoms."

The younger Khamenei has stayed largely silent since taking power March 8. Iranian officials say he's still consolidating control and cannot make major concessions without risking a challenge from the IRGC.

That's the problem.

Economic warfare by numbers

Every day the strait remains closed costs Iran $40 million in lost revenue and global markets $2.3 billion in higher energy costs. European refiners have started rationing diesel. Asian buyers are scrambling for alternative supplies.

But Iran's calculation isn't purely economic. Keeping Hormuz closed forces the world to pay attention to its demands — opening it removes Iran's only remaining leverage.

"They're betting that global economic pressure will force the US to offer better terms," said Sanam Vakil, deputy director of the Middle East program at Chatham House. "It's a dangerous game, but it's the only card they have left."

Oil traders are watching the talks closely. Brent futures for June delivery jumped $3.20 on Friday as investors priced in the possibility of extended closures.

Pakistan's desperation

Islamabad has its own reasons for wanting a deal. Pakistan imports 35% of its oil through the Strait of Hormuz, and the closure has triggered fuel shortages across the country.

Prime Minister Shehbaz Sharif spoke with both Trump and Mojtaba Khamenei this week, urging compromise. Pakistani officials say they've prepared three fallback proposals if the main negotiations fail.

The most realistic involves a partial reopening of Hormuz for civilian tankers while military vessels remain banned. Iran would get limited sanctions relief in exchange.

But even that faces obstacles. Israel has threatened to resume strikes if Iran shows any sign of nuclear advancement. The US Congress is preparing new sanctions legislation. And Iranian hardliners are calling any compromise a betrayal.

The talks are scheduled to run through Thursday. If they fail, analysts expect Iran to begin installing advanced centrifuges at its Fordow facility — crossing what Israel has called a red line.

Markets will have their answer by Friday's close.