Faced with Israeli warnings of strikes against Iran’s nuclear facilities, officials here routinely answer with bravado and counterthreats.

The Shiite Muslim clerics who rule the country laud the might of Iran’s armed forces, and military commanders boast that the country could shoot “150,000 missiles to Israel” if one Israeli bomb struck Iranian territory.

Instead of sharing that sense of defiance, however, many ordinary Iranians are increasingly worried that war could be catastrophic.

In the subway, on the streets and at private gatherings, Iranians are debating the possibility of war and how to protect their families if it should come.

As tension rises, many have started taking precautionary measures. Some are stocking up on basic goods. Others are changing their money into foreign currencies, or obtaining visas to move abroad.

Arash, an interior designer, recently decided to buy bags of rice and fill his new freezer with chicken and meat, just in case. “I feel that we will witness great instability, either through war or a collapse of power, so I am preparing myself,” said Arash, who, like others, declined to allow his last name to be used out of concerns for his safety.

Like many in the capital, he is carrying out basic, simple safety measures. But Arash has taken the additional step of applying for a U.S. green card.

“After 30 years of living with foreign pressure, Iranians have grown accustomed to keeping their options open,” he said. “Whatever happens, I want to be prepared.”

Fears that something will happen soon have been growing of late. Israel’s defense minister said this month that the country may have no other option than to launch a military strike in order to halt Iran’s fledgling nuclear program. The Obama administration has asserted that all options are on the table in dealing with Iran.

While Iranian leaders say their nuclear ambitions are purely peaceful, most Western leaders believe that the country is seeking to build nuclear weapons.

Concerns among Iranians have been heightened by recent events within the country.

A mysterious explosion at a missile base near Tehran last month rocked the capital and led many to believe that an attack was underway. Weeks later, all British diplomats left Iran after an attack on their compounds. In recent days, the capture of a sophisticated CIA drone that Iran says had been flying over its territory has solidified the sense that the country is drifting toward conflict.

“We Iranians can be like chickens which just had their heads cut off; it takes us a while to realize what has happened” said Mehrdad, a computer engineer. “People are now starting to think that war is inevitable.”

Mahnaz Mahjori, a psychological therapist, said Iranians are used to living under pressure. People here have dealt with a devastating eight-year war with Iraq during the 1980s, decades of sanctions and cutthroat political infighting.

“None of my patients have sought my counsel regarding war fears,” she said. “But my friends and I all talk about it. We are concerned what sort of change is waiting for us.”

Anxiety is also being fueled by the latest rounds of international sanctions against Iran. While Iranian officials continually say the country can cope with the growing limitations, average Iranians are faced with soaring prices and a plummeting exchange rate for their currency, the rial. It has lost 48 percent of its value against the dollar since 2008.

For now, Iran’s economy is being kept afloat on the strength of its oil revenue. But most people feel that the sanctions will only increase, slowly but surely also affecting Iran’s ability to sell oil. “If there is to be an oil embargo, our whole economy will crash,” said Masoud Niktab, 31, a bookseller near Tehran University. “At that point, common people will face the most hardship.”

Members of Iran’s urban middle class — from bus drivers to lawyers and artists — say they feel increasingly caught between the defiant behavior of their rulers and the pressures exerted by the West, including the United States.

Many say they feel hopeless and see no solutions to their problems. Some even say they would welcome anything that would create change in Iran, even if the change is tumultuous.

“In a way, many of these events — sanctions and threats — make me happy,” said Niloofar, a painter. “Because I feel things here need to change, no matter how.”