CAIRO, JULY 18 -- Iraq has accused its wartime ally Kuwait of stealing Iraqi oil, building military installations on its territory and reducing its oil income by cooperating with an "imperialist-Zionist plan" to depress oil prices through overproduction.

Iraqi Foreign Minister Tariq Aziz made the charges against the desert sheikdom in a letter to the Arab League made public today. A day earlier, Iraqi President Saddam Hussein charged that some Persian Gulf states had stabbed Iraq in the back "with a poison dagger" by exceeding their oil-production quotas in what he said was a U.S.-led conspiracy to ensure cheap petroleum prices.

Saddam Hussein added ominously that "if words fail to protect Iraqis, something effective must be done to return things to their natural course and return usurped rights to their owners."

The Iraqi outburst is the latest move in what appears to be an aggressive campaign by Saddam Hussein to impose his will on other Arab states, particularly his neighbors in the Arabian Peninsula who are fellow members of the Organization of Petroleum Exporting Countries.

In Washington, a State Department spokesman said the United States remains "strongly committed to supporting the individual and collective self-defense of our friends in the gulf with whom we have deep and longstanding ties," but he declined to say whether the United States would provide Kuwait with military help against an Iraqi attack.

Kuwait, one of the world's major oil producers, convened an emergency session of its National Assembly today to discuss the Iraqi threats. Saad Abdullah Sabah, the crown prince and prime minister, told the assembly that the government viewed the situation as critical.

Foreign Minister Sabah Ahmed Sabah left the closed meeting, saying he was flying to Saudi Arabia and other gulf states "to inform them about Kuwait's position on the Iraqi note." Two other top-level emissaries were sent to other Arab states.

Kuwait's swift and public response appears to indicate it is taking the Iraqi threats seriously. Western diplomats reached by phone in Kuwait said they were unable to tell if the government expects an Iraqi military attack, but one added that Kuwait, squeezed between Saudi Arabia and Iraq, does "feel threatened."

Aziz's nine-page letter, delivered to the Arab League Monday and broadcast today by Iraq's state-run radio, also attacked the United Arab Emirates for exceeding its oil-production quota. Baghdad has charged repeatedly that overproduction by Kuwait and the Emirates has caused oil prices to slide from $21 to $16 a barrel in the last seven months.

Iraq's charges took many observers by surprise, since just last week Kuwait and the Emirates, under Iraqi and Saudi pressure, agreed to stop exceeding their quotas in preparation for an OPEC meeting next week in Geneva. After Iraq's accusations today, officials in both countries said they would abide by that agreement.

Some oil market analysts suggested that Iraq's threats might be designed to set the stage for it to demand even higher oil price targets than those proposed for discussion at the coming OPEC session.

During Iraq's eight-year war with Iran, Kuwait and other gulf states provided Baghdad with arms and an estimated $30 billion in loans and credits, largely because they saw a greater threat in Iran's revolutionary Islamic regime. But with the war over, they are watching Saddam Hussein's aggressive bid for Arab leadership with some trepidation, Western diplomats said.

In Kuwait's case, Iraq has refused repeatedly to discuss a longstanding border dispute or publicly disavow territorial claims on the Kuwaiti islands of Bubiyan and Warba, diplomatic sources in Kuwait said.

The gulf states' fears over Saddam Hussein's intentions have grown just as their decade-long concerns about Iran's attempts to export its revolution are fading in the wake of conciliatory diplomacy from Tehran.

Last week, Iranian Foreign Minister Ali Akbar Velayati concluded what both sides called a successful visit to Kuwait, capping a months-long reconciliation. The two countries recently agreed to restore maritime traffic and air links, and Iran, which already has an ambassador in Kuwait, has accepted Kuwait's designated envoy to Tehran, officials said.

In renewing ties with Iran, Kuwait is reverting to its historical strategy of protecting itself by playing off its two large northern neighbors against each other, Western diplomats in Kuwait said.

Aziz's letter alleged that Kuwait began to "steal" oil worth $2.4 billion from Iraqi fields shortly after the outbreak of the gulf war. He said Kuwait then began "flooding the world oil market . . . causing a double harm for Iraq: weakening its economy at a time when it was in great need of revenues and stealing its wealth."

Aziz also complained that Kuwait and the Emirates had declined to cancel Iraq's war debts.

On Tuesday, Saddam Hussein said the sharp drop in oil prices in the first half of 1990, which cost Iraq $14 billion in revenue, was the result of a U.S.-planned "subversive policy" intended to "secure the flow of oil . . . at the cheapest prices."

During the gulf war, Washington provided Kuwait with naval protection, and five Kuwaiti vessels still sail under the U.S. flag. Washington said the operation was aimed at deflecting Iranian aggression, but some Western diplomats in Kuwait said it also has served, especially since the end of the war, to keep hostile Iraqi designs against Kuwait in check.