Iran is turning up the heat on the United States and its allies by shifting away from a policy of "strategic patience" and pushing back against Washington's campaign of "maximum pressure" -- which has significantly cut Iran's oil exports, a major source of income, and caused the economy to shrink.
Tehran has signaled recently that it is ready to resume sensitive nuclear activities and disrupt security in the strategic Strait of Hormuz, a major route for the world's oil supplies.
But the decision raises the risk of miscalculation by Tehran and a military confrontation with the United States, analysts warn.
"Iran is trying to meet U.S. pressure with its own pressure to force the international community to act or the U.S. to back down," said Rand Corporation analyst Ariane Tabatabai, who believes the recent developments have led to "a new phase" of tensions between Washington and Tehran.
"The challenge being that the Iranians may think they can control the current escalation, but they can lose that control very quickly and end up with more than they had bargained for," Tabatabai added.
Tehran announced on June 17 that in 10 days it will surpass a limit on its uranium-stockpile set by a 2015 nuclear deal between Tehran and world powers that curbed Iran's nuclear program in exchange for relief from crippling economic sanctions.
The move would put Iran in breach of a key element of the nuclear agreement, which Tehran has continued to comply with despite last year's withdrawal by the United States from the pact and the reimposition of crippling sanctions.
Iran's announcement comes following an attack on two oil tankers in the Gulf of Oman, which the U.S. has blamed on Tehran.
Washington also blamed Tehran for last month's attacks on oil-carrying vessels off the coast of the United Arab Emirates.
Iranian officials, who have repeatedly threatened to close the Strait of Hormuz, rejected any involvement in the attacks on the ships while blaming Tehran's "enemies," including the United States, for the incident.
Officials have also publicly rebuffed an offer from U.S. President Donald Trump for talks with the country's highest authority, Supreme Leader Ali Khamenei, stating that Trump was not "worthy" of an exchange of messages.
'Not Much Time Is Left'
Speaking on June 17, the chief of the general staff of Iran's armed forces, Mohammad Bagheri, said that if the Islamic republic decides to block the Strait of Hormuz it would do it openly and in a way that "not even a drop of oil will pass."
Ali Vaez, the Iran project director at the International Crisis Group (ICG), tells RFE/RL the campaign of "maximum pressure" by the Trump administration has brought "Iran's maximum patience policy" to an end.
Vaez notes that Iranian retaliation is still "measured and reversible," but he adds that "sooner or later, they'd violate the nuclear deal or commit a mistake that could lead to a regional conflagration."
Vaez believes Iran is trying to pressure the remaining parties to the nuclear deal, Britain, China, France, Germany, and Russia, to help the country weather U.S. sanctions and deter the United States from further ratcheting up the pressure.
Speaking on June 17 at Arak's heavy-water nuclear reactor, Iranian Atomic Energy Agency spokesman Behruz Kamalvandi said there was still time for the European countries to act in order to salvage the deal. EU countries have so far failed to activate a financial vehicle created to help Iran circumvent U.S. sanctions and benefit from the deal economically.
But he warned that Iran could reactivate the reactor to make plutonium, which can be used in the production of nuclear weapons.
"The message that we tried to get across to the Europeans today was that not much time is left for them," Kamalvandi said.
Ali Ansari, the director of the Institute for Iranian Studies at the University of St. Andrews, said Iran wants to send the message to the outside world that "they can kick back against the growing pressure and realize some of the threats they have been making over the past few weeks."
The measure could be also an attempt by Tehran to buy time and gain leverage.
"Iran doesn't want to help Trump get reelected and some policymakers in Tehran have argued that talks would benefit the President," says Sanam Vakil, a senior research fellow in the Middle East-North Africa Program of the Royal Institute of International Affairs.
"At the same time, though, they are gambling on the chance that with a new president [if Trump were to lose the 2020 presidential election], the negotiating terms will be less stringent," Vakil adds.
Hossein Alizadeh, a former Iranian diplomat and a researcher at the Peace Research Institute at the University of Tampare in Finland, told RFE/RL that on the outside Iran is trying to demonstrate that it is ready for a confrontation -- "even for a war."
But he says the measures Tehran has taken so far amount to a "very slow" shift and a calibrated response to the intense pressure it is facing.
Alizadeh believes Tehran was not behind the June 14 attack on the Norwegian-owned Front Altair and Japanese-owned Kokuka Courageous that occurred just south of the Strait of Hormuz.
"It doesn't make sense for Iran to attack tankers while [Japanese Prime Minister] Shinzo Abe was meeting with Khamenei amid the conditions of pressure the country faces," Alziadeh told RFE/RL, while also noting that his assessment does not negate the fact that the Islamic republic has been involved in "acts of sabotage" in the past.
Other analysts, Iran watchers, and current and former U.S. officials have said that the evidence, although not conclusive, points towards Iran.
"There's no question that Iran is behind the attacks," Adam Schiff, the chairman of the House Intelligence Committee, said in a June 16 interview.
"I think the evidence is very strong and compelling; in fact I think this is a Class A screw-up by Iran," Schiff said on U.S. television over the weekend.
Amid the quickly escalating tensions, both the United States and Iran have said they are not seeking a war.
"The United States does not seek conflict with Iran," acting Defense Secretary Patrick Shanahan said on June 17 while announcing the deployment of 1,000 more troops to the Middle East.
He said the move was intended "to ensure the safety and welfare of our military personnel working throughout the region and to protect our national interests."
Speaking one day later, Iranian President Hassan Rohani said his country does not "wage war with any nation."