THE Persian Gulf is an international waterway. Neutral shipping is entitled to freedom of passage through it at all times. Kuwait is a neutral in the Iraq-Iran war, although its sympathies are openly on Iraq's side, and it has given aid to Iraq. There is warfare in the Gulf. The Iraqis, who have been the weaker side in the land war, have the advantage in the air war. The Iraqi population is 15 million, against 45 million Iranians. But the Iraqis are estimated to have 500 serviceable combat aircraft, against 68 for the Iranians.
The land war is stalemated. The Iraqis are entitled under international law to use their aircraft against Iranian shipping in the Gulf. Iran is entitled to retaliate in kind but cannot, because there is no Iraqi shipping in the Gulf. Iran controls the mouth of the Tigris and Euphrates Rivers. Iraq is bottled up. Its oil goes out through pipelines through Turkey and Saudi Arabia.
Iraq benefits indirectly from the flow of oil from Kuwait, Qatar, Bahrain, Saudi Arabia, and the United Arab Emirates through the Gulf to the outside world. They are all Arab states and all give some help to Iraq. Iran has done some, but not much, shooting at ships carrying Arab oil, although they are all technically neutral.
Most of the shooting in the Gulf war has been by Iraq's superior Air Force against Iranian oil terminal facilities at Karg Island, and at Iranian tankers.
Iran probably has the physical ability to halt the flow of oil from Kuwait, Bahrain, Qatar, and Saudi Arabia, because Iran is the largest naval power among the Gulf states. Iran has three destroyers, four frigates, and two corvettes. No other Gulf state has anything larger than a frigate. Mostly they have high-speed torpedo boats.
That is where the United States comes into the picture. Until 1971, Britain was the policeman of the Gulf. It maintained a substantial naval presence and ensured the undisturbed flow of oil from the Gulf to the outside world.
In 1971, Britain ceased to be the policeman of the Gulf. In effect, it handed the job over to the US. The US has, somewhat hesitantly, taken over. It now maintains the largest naval presence in the Gulf, although there are also British, French, and Russian patrol craft there from time to time.
The central question has been whether the US, for the sake of the importance of the flow of Arab oil out of the Gulf to the industrial world, would protect the right of the neutral Arab countries to continue to ship their oil through the Gulf.
Insofar as Iraq benefits indirectly from that flow of oil, the protection of it is a disadvantage to Iran. But the flow is neutral. The ships carrying it are neutral. Under international law Iran should not be shooting at neutral ships, even though some of the profit from the sale of the oil may find its way to Iraq.
The US has the same right to protect its shipping, and the shipping of friendly countries, in the Gulf as anywhere else. As the major sea and air power of the industrial democracies, it is the logical one to do most of the police work. No one denies that the US has a right to protect neutral shipping in the Gulf, although others would have the same right, including the Russians, if they chose to exercise it. The only special right the US has is as the heir to the former British position in the Gulf.
The US has in this case elected to play the policeman role in the Gulf. In theory, it is doing it to uphold the rights of neutral shipping. In fact, it is done to bolster Iraq, which is almost exhausted from its losses in the war, now in its seventh year.
Policemen sometimes get hurt. So far the damage is one tanker holed by one mine. Probably there will be more damage to the policeman or to the tankers he is trying to protect. It won't be a free ride.
But the alternative was to leave the policing job to others. The Russians might well have enjoyed the opportunity to take over. If they did not, then neutral shipping would be at the mercy of Iran.
There was no easy alternative for Washington.