• Trump announced a ceasefire between Israel and Iran, but it's already showing signs of strain.
• Tehran may turn to proxies, missiles, or the Strait of Hormuz if the conflict reignites.
• Analysts told BI that Iran's options are limited and it risks a strong backlash.

Despite being outmatched by Israel's advanced arsenal, Iran retains several military options should the fragile ceasefire first announced by President Donald Trump collapse.

On Monday, Trump announced that the US had brokered a "complete and total" truce between the two countries, but since then there have already been signs that the deal is on shaky ground.

By Tuesday morning, Trump was urging restraint on Truth Social, calling on both countries to "not violate" the ceasefire. He later urged Israel to avoid "dropping those bombs," or risk committing a "major violation."

Ongoing covert operations and missile launches have already chipped away at its credibility, Andreas Krieg, a Gulf specialist at the Institute of Middle Eastern Studies at King's College London, told Business Insider.

"The ceasefire that took effect following US and Qatari mediation is brittle and fragile," Krieg said. "It rests more on political signaling and public posturing than on concrete enforcement mechanisms."

He added: "In practice, the ceasefire has mostly existed on social media, with each side using digital platforms to declare restraint while continuing activities that fall short of open warfare."

Mining or threatening the Strait of Hormuz

"There is a case where a ceasefire could hold," Chris Doyle, director of the Council for Arab British Understanding, told BI, "but there's also a case sort of saying that both sides want to be the last to fire."

If the ceasefire collapses, Iran's most powerful geopolitical lever remains the Strait of Hormuz — a vital 21-mile-wide chokepoint through which 20% of the world's oil flows.

Iran has long threatened to block it.

While Iran lacks the legal authority to shut down the Strait of Hormuz outright, it could cripple global energy markets by making the waters barely navigable.

"Under normal circumstances, this might be seen as a self-destructive option given Iran's own dependence on revenue from oil exports through that corridor," Jacob Parakilas, a research leader for Defence Strategy, Policy and Capabilities at RAND Europe, told Business Insider.

"But if Israeli strikes cause enough damage to Iranian oil infrastructure, that calculation might well change," he said, adding that Iran could use missile-armed small boats, drones, and naval mines.

"This arsenal could pose a significant challenge to navigation," said Sidharth Kaushal, a sea power expert at the Royal United Services Institute think tank.

Kaushal said the US Navy is equipped to counter this, but the time needed to do so would be costly for all involved.

A full closure of the Straits could push Brent crude past $110 a barrel, according to Goldman Sachs.

Attacks on US bases

Iran launched a missile strike on Monday on Al Udeid, the largest US base in the region. This was before the ceasefire was announced.

While Qatar said its air defense systems intercepted the missiles, and no casualties were reported, the attack showed Tehran's willingness to target US bases.

The US has bolstered its regional strength by deploying carrier strike groups and missile defense systems and repositioning aircraft, including B-2 bombers, away from vulnerable sites like Al Udeid.

However, Doyle believes that Iran is unlikely to escalate directly against the US.

Instead, he said that Iran's strategy could be to prolong the conflict with Israel, aiming to outlast its will politically and economically.

He described this as a war of attrition, rather than one of decisive strikes. "Whilst these dangerous weapons are still being used, anything can happen," he said.

Proxy groups

Beyond direct military action, Iran has long relied on its network of proxy forces — Hezbollah in Lebanon, Shia militias in Iraq and Syria, and the Houthis in Yemen.

These offer Tehran plausible deniability and the ability to hit Israel or US assets without direct confrontation.

But Iran's proxies are not what they once were.

Israel's offensives have decimated Hamas' military leadership and driven Hezbollah into retreat after heavy airstrikes and an incursion into southern Lebanon. Meanwhile, President Bashar Assad has been ousted in Syria.

The deaths of Hezbollah leader Hassan Nasrallah and Ismail Haniyeh, the leader of the political wing of Hamas, have further degraded Tehran's reach.

Edmund Fitton-Brown, a senior advisor to the Counter Extremism Project, cautioned that Tehran may already be close to exhausting its proxy playbook.

These groups "are already doing everything they can," he said.

"Iran cannot supply the proxies — the Houthis are under siege," he added. "The main threats to the Americans would be from the Iraqi proxies, and even they may act independently rather than under direct Iranian command."

Activating these forces en masse also risks broader escalation, especially if unconventional weapons are used.

Ballistic missile capabilities

While Iran's air force can't compete with Israel's, its ballistic missile arsenal has expanded into the largest in the region.

Tehran now possesses an estimated 3,000 missiles, including a growing stockpile of solid-fueled, precision-guided medium-range weapons like the Fattah-1 and Kheibarshekan, which were both used in an attack on Israel last October.

But experts say these, too, have been significantly reduced.

Iran's "ballistic missile supply is not infinite and has already decreased significantly," Yaniv Voller, a senior lecturer in Middle East Politics at the University of Kent, said.

Fitton-Brown agreed: "They've mainly been depleted because they've been used — and the Israelis have taken aim at military-industrial sites."

No good options

Browne Maddox, director of the Chatham House think tank, wrote in a Sunday briefing that few of the choices available to Iran are attractive to it.

But it may still go for them "rather than be seen to be forced back to the table," she said.

It's also a delicate matter for the country domestically.

Being forced by the US to give up its nuclear enrichment — a key demand of the Trump administration — "would very likely be perceived by Iranians as surrender," she said.

One option for Tehran, she said, is to draw out negotiations while quietly rebuilding its nuclear program, taking advantage of ongoing disagreements in the Trump camp over how best to proceed.

But all its military options risk a devastating US or Israeli response.

"Iran doesn't have good options," Fitton-Brown said. "It's run out of them."

• Israel targeted nuclear and military sites in Iran in airstrikes early Friday morning.
• The strikes are a major escalation that threatens to expand into a wider regional conflict.
• These are five key questions in the wake of Israel's air war.

Israel's widespread airstrikes on Iran effectively damaged the country's nuclear and ballistic missile programs, which officials said was a primary goal.

The strikes hit over 100 targets, including Iran's air defense systems, missile launchers, and senior military leadership.

Now, all eyes are on Tehran's response and the specter of a wider conflict. And there are questions over whether the US will get pulled into the fight.

Here are some main questions stemming from the attacks.

How has Iran responded?

Iran initially responded to the attack by firing 100 drones at Israel on Friday, which the Israel Defense Forces said were mostly intercepted.

Iran's Supreme Leader Ayatollah Ali Khamenei said Israel "should anticipate a severe punishment" in response to the strikes, and that Iran "won't let them go unpunished."

Hours later, the IDF said Iran had launched "dozens" of missiles at Israel in what appeared to be several waves. The military said its air defenses were actively intercepting threats, and video footage captured several impacts.

"The Iranian response might be delayed or split into multiple phases," said Matthew Savill, the director of military sciences at the UK-based Royal United Services Institute think tank.

"But their main weapon will be ballistic missiles," he added, "which have the best chance of inflicting damage on Israel, whereas drone and cruise missile attacks will face more extensive Israeli defences."

It is not unprecedented for Iran to launch powerful weapons at Israel; Tehran fired hundreds of missiles and drones at its foe in April and October last year. However, those strikes were mostly intercepted by Israel and its allies, including the US.

Beyond direct strikes, another way that Iran could retaliate is through the so-called "Axis of Resistance," a vast network of militias it is aligned with throughout the region, including Lebanon's Hezbollah and Yemen's Houthis.

Israel has been battling these forces, and Hamas in Gaza, since the October 7, 2023, attacks.

Israeli Prime Minister Benjamin Netanyahu has long advocated for destroying Iran's nuclear program, which Tehran claims is for civilian purposes.

The US, however, has been trying to reach a new deal with Iran (and has threatened violence if a deal isn't done). The strikes could derail those efforts and even goad Iran into racing to build a nuclear arsenal.

Could this trigger a wider conflict?

Israel's strikes threaten to spark a wider regional conflict, analysts at London's Chatham House think tank warned Friday.

"Far from being a preventive action, this strike risks triggering a broader regional escalation and may inadvertently bolster the Islamic Republic's domestic and international legitimacy," Sanam Vakil, Chatham House's Middle East and North Africa program director, said.

Last year, Tehran reportedly threatened to target Gulf state oil facilities if they allowed Israel access to their airspace for strikes against Iran. It's unclear what routes Israeli aircraft used in the attacks, but there's been speculation Israel could exploit the collapse of the Assad regime in Syria to get its aircraft directly over Iraq for strikes.

Russia is also a close ally of Iran, and the two have increased their defense cooperation since Russia launched its full-scale invasion of Ukraine in 2022.

However, Nikita Smagin, an analyst at the Carnegie Endowment, said in December that the Kremlin is unlikely to come to Iran's direct aid in order to avoid direct confrontations with Israel and the US.

Will the US be pulled into a fight?

The US has helped arm and defend Israel, notably in the wake of Hamas' October 7 attacks. The world will be watching to see how President Donald Trump responds.

Trump has sought to broker a new nuclear deal with Iran, and in the wake of the Israeli attacks overnight, warned of "even more brutal" strikes from Israel if Iran refuses a new agreement.

Last year, the US Navy helped shoot down Iranian missiles fired at Israel in two major attacks, and it has rotated multiple aircraft carriers and many warships into the region since 2023, in a show of support for Israel and to deter its enemies, including Iran.

The US and other NATO countries have also defended international shipping routes in the Red Sea and the Gulf of Aden from attacks by the Iran-backed Houthi militants in Yemen.

What forces does the US have in the region?

The US has a substantial military presence in the Middle East, including naval forces, ground troops, and strike aircraft.

A Navy spokesperson told BI that the Carl Vinson Carrier Strike Group — consisting of an aircraft carrier, a cruiser, and three destroyers — is in the Arabian Sea.

There are also three American destroyers in the Red Sea and another in the Eastern Mediterranean.

All of these warships, and the carrier's dozens of embarked aircraft, are capable of carrying out air defense missions to defeat incoming drones and missiles.

Were the strikes effective?

IDF spokesperson Brig. Gen. Effie Defrin said Israel's strikes "significantly harmed" Iran's main uranium enrichment site at Natanz.

"For many years, the people of the Iranian regime made an effort to obtain nuclear arms in this facility," he said, adding that the site "has the necessary infrastructure to enrich uranium to a military grade."

The International Atomic Energy Agency has confirmed the site was struck, but the extent of the damage remains unverified.

Satellite imagery appeared to show significant damage at the surface level.

There was also a report Friday that Israel had struck Fordow, a nuclear fuel enrichment site guarded deep under a mountain.

The IDF said that Iran's Islamic Revolutionary Guard Corps chief Hossein Salami and other senior military commanders were also killed in targeted strikes.

• The Royal Navy is building 12 new SSN-AUKUS attack submarines.
• They're set to replace the UK's Astute-class attack submarines by the 2030s.
• It comes as part of the UK government's bid to boost its armed forces amid rising global threats.

The UK plans to build 12 new attack submarines as part of sweeping plans to boost the country's military.

The Ministry of Defence said Sunday that the SSN-AUKUS vessels would be built as part of the UK's Strategic Review to enhance its military strength amid rising global threats.

They'll be deployed as part of the AUKUS alliance between the UK, Australia, and the US, with the submarines having been developed alongside the Australian navy.

"Our outstanding submariners patrol 24/7 to keep us and our allies safe, but we know that threats are increasing and we must act decisively to face down Russian aggression," UK Defence Secretary John Healey said.

He added: "With new state-of-the-art submarines patrolling international waters and our own nuclear warhead programme on British shores, we are making Britain secure at home and strong abroad, while delivering on our Plan for Change with 30,000 highly-skilled jobs across the country."

The submarines are set to replace the UK's current fleet of seven Astute-class attack submarines by the 2030s.

The Astute class submarines are nuclear-powered and carry Tomahawk Land Attack Cruise Missiles (TLAM) and Spearfish heavyweight torpedoes, the UK government said.

The Naval Lookout analysis website described the new submarines as an "apex naval predator."

"In preparing for potential conflict with other states, SSNs are arguably the most important conventional assets the UK can deploy," it said, adding that they can be used to take out enemy vessels, create blockades, land special forces operatives, and gather intelligence.

But Matthew Savill, director of military sciences at the Royal United Services Institute, told journalists that questions remain over how the target of building 12 submarines would be met on schedule.

"There is going to have to be a pretty major culture change within the forces, within the MOD and their relationship with industry to make that more viable," he said.

"I would be fascinated to know how they're going to do that because the record is not great up until now," he added.

The UK government has pledged to boost defense spending to 2.5% of GDP by 2027.

Under the plans outlined in its latest Strategic Defence Review, released this week, it will also provide the equivalent of $20 billion in extra funding for the UK's nuclear weapons program.