Did Trump authorise Israel's strike on Iran, and is US heading to war?

As tensions escalate between Iran and Israel, the administration of United States President Donald Trump is sending conflicting messages on whether it still supports a diplomatic resolution to Iran's nuclear programme.

While US officials had backed a negotiated agreement and were expected to meet with Iranian counterparts this week, Trump posted on Truth Social as recently as Thursday: "We remain committed to a Diplomatic Resolution."

But just 14 hours later, after Israel launched its attack on Iran, Trump posted that he had given Tehran a 60-day deadline to reach an agreement — and that the deadline had expired, reports Al Jazeera.

By Sunday, he appeared to shift again, urging: "Israel and Iran should make a deal" and suggesting it could happen with his help.

On Monday, ahead of his early departure from the Group of Seven summit in Canada, Trump escalated his rhetoric, posting: "Everyone should immediately evacuate Tehran!" He also stated that Iran must not acquire a nuclear weapon. Addressing speculation that he had returned to Washington, DC, to mediate a ceasefire, Trump said it was for something "much bigger than that."

These ambiguous signals have stirred debate among analysts about the true nature of U.S. involvement and the direction of its policy.

Trump's 'wink and a nod'?

Trump has firmly denied US involvement in the Israeli strikes on Iran. "The US had nothing to do with the attack on Iran, tonight," he wrote on Sunday.

Still, experts remain divided. Kelsey Davenport, director for nonproliferation policy at the Arms Control Association, said Trump's position has been relatively consistent: "I think that President Trump has been very clear in his opposition to the use of military force against Iran while diplomacy was playing out. And reporting suggests that he pushed back against [Israeli Prime Minister Benjamin] Netanyahu."

Davenport speculated that Israel may have acted out of fear that diplomacy would succeed. "Israel was worried that diplomacy would succeed, that it would mean a deal," she said, adding that Israel likely viewed such an outcome as not aligning with its goals.

Richard Nephew, a Columbia University professor and former US National Security Council director for Iran under President Barack Obama, agreed. "I think it is that consistency that's actually been the thing that's the problem," he said, referring to Trump's push for a deal.

However, Ali Ansari, professor of Iranian history at St Andrews University in Scotland, took a different view. "The US was aware. … Even if the specific timing did surprise them, they must have been aware, so a wink is about right," he told Al Jazeera.

He added, "At the same time, the US view is that Israel must take the lead and should really do this on their own."

Is Trump being pulled into war?

Israel reportedly destroyed the above-ground section of Iran's uranium enrichment facility at Natanz, which enriches uranium up to 60 percent purity — well above the threshold for civilian energy use, but below weapons-grade levels. The International Atomic Energy Agency (IAEA) believes power loss caused by the attack may have also affected the underground section of the site.

However, Iran's other major enrichment site at Fordow, built into a mountain, appears to have escaped damage, according to the IAEA.

Davenport noted that striking underground facilities like Fordow would require more firepower than Israel currently possesses. She pointed to the US's Massive Ordnance Penetrator, a 13,600kg (30,000lb) bomb. "[With] repeated strikes with that munition, you could likely damage or destroy some of these facilities," she said, while noting: "Washington has not transferred that bomb to Israel."

Barbara Slavin of the Stimson Center echoed the point, stating that Israel would need U.S. weapons to accomplish its goal of eliminating Iran's nuclear capability.

Nephew added, "We know that [Trump] likes to be on the side of winners. To the extent that he perceives the Israelis as winners right now, that is the reason why he is maintaining his position and why I think we have a wink [to Israel]."

The US military has also taken visible steps in the region, deploying midair-refueling aircraft and dispatching the USS Nimitz aircraft carrier. More warplanes were sent on Tuesday, further raising questions about America's next move.

Ansari suggested Trump could be drawn into the conflict out of political calculation: "Trump is tempted to join in just to get some of the glory." Still, he believes that even the threat of US intervention might compel Iran to de-escalate. "They can concede – with honour – to the United States; they can't to Israel, though they may have no choice."

Congress pushes back

In light of rising tensions, Senator Tim Kaine introduced a war powers resolution requiring congressional approval for any military action against Iran. "It is not in our national security interest to get into a war with Iran unless that war is absolutely necessary to defend the United States," Kaine said.

Diplomacy or force?

Under President Obama, the US opted for diplomacy through the Joint Comprehensive Plan of Action (JCPOA), which was signed in 2015. The agreement mandated IAEA inspections and limited Iran's uranium enrichment.

Both Nephew and Davenport argue that Trump undermined the diplomatic path when he withdrew from the JCPOA in 2018, under pressure from Israel. Since then, Iran has steadily increased its uranium enrichment levels — reaching 83.7% at Fordow by 2023.

Nephew blamed the shift: "Setting [the JCPOA] on fire was a direct contribution to where we are today." He warned that pursuing a military solution rather than diplomacy could accelerate nuclear proliferation: "Because countries say, 'The only way I can protect myself is if I go down this path.'"

Davenport added that even regime change, as called for by Netanyahu, would not guarantee disarmament. "Regime change is not an assured nonproliferation strategy," she said. "We don't know what would come next in Iran if this regime were to fall. If it were the military seizing control, nuclear weapons might be more likely. But even if it were a more open democratic government, democracies choose to build nuclear weapons too."