The United States has assembled what officials describe as the largest military buildup in the Middle East in decades, deploying two aircraft carrier strike groups and surging air and naval assets across the region as it pushes Iran to reach a deal on its nuclear program. Talks between the two countries resumed Thursday in Geneva under Omani mediation. Whether they produce anything is another question.

President Donald Trump set a rough timeline last week, saying Iran had "10 to 15 days, pretty much maximum" to show progress at the table. "You're going to be finding out," he told reporters. He has not ruled out a military strike — limited or otherwise — if negotiations stall.

Iran says it is close to presenting a draft proposal. Its foreign minister, Abbas Araghchi, told CBS on Sunday that a "good chance" remains for a diplomatic outcome. But Tehran has been equally direct about what it will not accept — and about how it would respond to any military action.

What Washington Wants, and Where Tehran Draws Its Lines

The American position centers on three demands: Iran must give up most of its nuclear program, limit its ballistic missiles to short ranges, and stop funding armed groups across the Middle East.

Tehran has taken the last two off the table entirely. On the nuclear question, Iran insists its program is for civilian use. The West disputes that, pointing to uranium enrichment levels that U.S. officials say have no practical civilian application at the quantities involved.

U.S. special envoy Steve Witkoff said publicly that zero uranium enrichment is a non-negotiable red line for Washington. Iran is currently enriching uranium to 60 percent purity — well beyond the level needed for a civilian reactor, and, by Witkoff's description, "probably a week away from having industrial-grade bomb-making material." Witkoff, during a weekend interview, said Trump was puzzled by Iran's refusal to move in the face of the military pressure being applied. "Why, under this sort of pressure, with the amount of sea power and naval power that we have over there, why haven't they come to us," he said.

Iran's foreign minister responded on social media: "Curious to know why we do not capitulate? Because we are Iranian."

Iran's foreign ministry spokesman, Esmaeil Baghaei, was more explicit about the consequences of any strike. Any military action, he said, "even on a small scale, would be seen as an act of war." Iran, he said, "would react ferociously." Tehran's deputy foreign minister, Kazem Gharibabadi, warned that the fallout from any attack "wouldn't remain confined to one country."

Inside the Pentagon's Concerns

Behind closed doors, the U.S. military's top officer has been raising his own set of concerns about what a conflict with Iran would actually require.

General Dan Caine, chairman of the Joint Chiefs of Staff, expressed reservations at a White House meeting last week attended by Vice President JD Vance, Secretary of State Marco Rubio, CIA Director John Ratcliffe, Defense Secretary Pete Hegseth, and White House adviser Stephen Miller. According to people familiar with the discussions, Caine cautioned that the American munitions stockpile has been significantly depleted by the ongoing defense of Israel and support for Ukraine, and that any major operation against Iran would face added risk from a lack of allied support in the region.

Senior Gulf Arab officials told the Washington Post that Arab countries had informed Washington they would not allow their bases to be used for a strike against Iran.

The scale of what a strike would require is substantial. Taking out Iran's missile program alone would mean hitting hundreds of targets across a country more than three times the geographic size of Iraq — mobile launch sites, supply depots, air defense systems, and transportation networks. A campaign aimed at regime change would expand to thousands of targets and could last weeks or months.

Two munitions most critical for protecting U.S. personnel against Iranian ballistic missiles — THAAD interceptors and Patriot systems — have already been heavily drawn down by operations in Israel and Ukraine. The U.S. produces only a few hundred of each per year. Standard Navy ship-launched missiles used for defensive operations in the Red Sea have also been consumed rapidly, with some systems requiring two years or more to replace each unit.

The Defense Department requested nearly $30 billion from Congress to replenish high-end missiles and interceptors. The request was only partially fulfilled in last month's Pentagon budget.

Trump denied reports of Caine's concerns publicly, writing on social media that accounts of the general's reservations were "100% incorrect" and that any conflict with Iran would be "something easily won." The people who spoke about Caine's actual comments directly contradicted that characterization. The White House said only that Caine is a "talented and highly valued member" of the national security team and that Trump "listens to a host of opinions."

Protests Inside Iran

While Washington and Tehran exchange threats across diplomatic back-channels, Iranian university students have spent the past three days demonstrating against the government in Tehran.

Videos verified and geolocated by AFP showed students at al-Zahra University, an all-women institution in the capital, burning flags and chanting "down with the Islamic republic" and "we'll reclaim Iran." Separate reports documented protests at Tehran University and scuffles at Amir Kabir University.

The protests are a continuation of unrest that began in December, driven in large part by economic hardship in a country operating under the weight of years of international sanctions. The demonstrations peaked on January 8 and 9 before being put down by security forces. The U.S.-based Human Rights Activists News Agency recorded more than 7,000 deaths during that crackdown, while acknowledging the toll is likely higher. Iranian authorities have confirmed more than 3,000 deaths, attributing the violence to what they described as "terrorist acts" fueled by the United States and Israel.

The January crackdown did not end the unrest. Students returned to campuses this week as the new semester began.

Supreme Leader Ayatollah Ali Khamenei, 36 years into his tenure, faces simultaneous pressure from a deteriorating domestic economy, a renewed protest movement, and an American military force positioned across multiple fronts in the surrounding region.

What Comes Next

The Geneva talks represent the third round of indirect negotiations since the Trump administration reengaged with Iran. The first two rounds, held earlier this month, produced "encouraging signals," according to Iranian President Masoud Pezeshkian — though the fundamental gaps on enrichment and regional influence have not closed.

India, Sweden, Serbia, Poland, and Australia have all issued advisories in recent days urging their citizens to leave Iran. The United States ordered nonessential personnel and their families to depart the U.S. Embassy in Beirut, citing the regional security environment. A similar drawdown preceded the American strikes on Iranian nuclear facilities in June 2025.

China urged Washington publicly not to trigger new conflicts. Chinese ambassador Shen Jian, speaking at a disarmament conference in Geneva Monday, said Beijing "opposes unilateral bullying and the use of force in international relations."

Trump, asked Friday whether he could order a limited strike while negotiations continued, said: "I guess I can say I am considering that."