The United States could put pressure on Iran in many ways in the present crisis, but most of the options would be painful for Americans and would not guarantee a change in Iranian policy.
The United States could halt shipments of rice, corn, soybeans and other foodstuffs -- a step that officials acknowledge would cause severe hardship and economic dislocation, particularly in large Iranian cities that rely heavily on U.S. food.
However, a food embargo would also cost American farmers a $500 million a year market and might heighten anti-American sentiment in Iran.
The United States could also probably ground most of Iran's air force by depriving it of spare parts, but military anaysts say these parts probably could be obtained from other countries later.
From a tactical standpoint, severing such ties could also weaken moderate elements in the Iranian business, political and military establishments which have a vested interest in continuing the relationship with the United States.
And so it goes with a long list of other options that include freezing Iranian assets in this country, severing commercial and financial relations and ending the transfer of industrial technology to Iran.
The situation, officials concede, provides a frustrating lesson in the limits of any country's power in the current interdependent global economy.
Eight months after its revolution, Iran is still tied to the West through its oil exports, its $2 billion a year in food imports, banking arrangements and foreign companies still quietly functioning within its borders.
Yet this web of dependency is difficult to exploit for political purposes.
"We are experiencing the results of our own success in building an interdependent world after World War II," said a senior administration official.
Military intervention -- the maximum response to the seizure of hostages and the cutoff of oil -- has been ruled out by the Carter administration. The administration has attempted to show restraint in a number of ways. After the seizure of the hostages in Tehran, it decided against moving the aircraft carrier Midway from the Indian Ocean closer to Iran.
Experts on the Middle East and on petroleum questions have strongly supported this approach.
Former U.S. ambassador to Saudi Arabia James E. Akins has said that "anyone who proposes solving our energy problem by invading Arabia is a criminal, a madman or an agent of the Soviet Union."
Akins has taken issue with military experts who claim the United States could take over Middle East oil fields and get them operating in a few months. In the case of Iran, the situation would be complicated by the posibility that any occupiers would have to contend with harassment from the local population, he has noted.
Nevertheless, recent events have fueled militancy on this question.
"As the Organization of Petroleum Exporting Countries pushes the West toward the edge of economic survival, the option of a military response becomes more and more reasonable," wrote Business Week in its current issue.
The Carter administration's military policy toward Iran right after Khomeini came to power was to keep dealing with what it considered the cooler heads in the defense ministry and the armed services.
Iran did not intend to keep flying the complicated and expensive F14 fighters the shah purchased, defense officials told the Pentagon, but wanted to keep up the flow of spare parts needed for the rest of the war machine.
Without maintenance and spare parts, a modernized military like Iran's soon deteriorates. Planes become too dangerous to fly and armored vehicles break down and cannot be repaired. This is now happening.
The United States, partly because of Iran's dependence on its spare parts and technical help, had obtained considerable leverage over the shah's military forces. Pentagon leaders had hoped to retain this leverage.
But if all military shipments were stopped, Iran would have to let its American arsenal of weaponry deteriorate or turn to other industrialized nations for help, with the Soviet Union, France and Britain among the possibilities.
One area of vulnerability under study by the administration is Iran's dependence on huge amounts of U.S. food. Shipments of grain and other foodstuffs continued to move steadily to the grain port of Bandar e Shahpur during and after the revolution.
Iran needs to import about 1.5 million tons of wheat and 1.3 million tons of feedgrains for its poultry each year. The country now imports 30 percent of its food, and any shift from this pattern would be extremely disruptive to the Iranian diet, officials here say.
In the last few weeks there have been indications that the present government is attempting to shift its dependence on these vital food imports away from the United States. The last two cargoes of U.S. wheat totaling 64,000 tons left Portland, Ore., for Iran in early September, according to Department of Agriculture officials.
Subsequently, Australia announced it had agreed to provide Iran with 520,000 tons of wheat over the next five months, and there were rumors that Iran may soon sign up for another 1 million tons -- enough to take it through 1980. Sources said Iran paid $20 a ton above U.S. prices to buy the Australian wheat. To supplement its wheat supply, Iran has also turned to Turkey for 50,000 tons, which is being trucked there at high costs. Similarly, Iran apparently switched to Western Europe from the United States for supplies of vegetable oil in the last three months.
Nevertheless, U.S. officials said yesterday that Iran will still have to come here for large quantities of rice and feedgrains or face serious hardship and the possible "devastation" of its poultry industry.
Iran's poultry production depends on feedgrains and soybeans that are available in sufficient quantities only in the United States.
Iranian businessmen have contacted officials in Washington and international grain companies about buying more corn in the next few months. U.S. shipments of corn reached a record 94,000 tons in September. Iran will also have to turn to the United States for much of the 500,000 tons of rice it needs, since supplies are scarce in world markets.
American agriculture officials are markedly unenthusiastic about losing a market for farm products that has taken years to develop.