RICHARD MURPHY is assistant secretary of state for Mideast affairs in Washington. We are indebted to him for candor about why President Ronald Reagan wants to send more United States naval vessels into the Gulf to protect and escort Kuwaiti tankers carrying oil out of the Gulf. The US mission in the Gulf, he said, is to prevent the encroachment of ``hostile powers'' into a region ``vital to the West.'' He identified those hostile powers as being Iran and the Soviet Union.
Earlier, Secretary of State George Shultz said, ``We don't have any desire to see the Soviets assume a role in the Persian Gulf.''
The USSR is playing a role today in the Gulf. The Kuwaitis have invited the Soviets to lease Soviet tankers to Kuwait, and protect those tankers which are flying the Soviet flag by Soviet naval vessels.
The immediate story of how this happened dates from November of last year.
The Kuwaitis, and everyone else, were astonished to learn that the US was selling arms to Iran for American hostages. In the Middle East, the essential fact was that the US was doing this at a time when Iran was attacking ships carrying oil from Kuwait to the outside world.
Kuwait is an ally of Iraq and of Saudi Arabia. The three Arab states have had agreements since 1984 to coordinate their defenses.
The news of US aid to Iran meant in the eyes of the Arabs that the US, which had officially been boycotting Iran, was actually giving important military support to their enemy, Iran.
The reaction in Kuwait was to do the logical thing at the moment, which in their eyes was to turn to Moscow and invite Moscow to lease Soviet flag tankers to Kuwait, and to escort them in the Gulf with Soviet naval vessels.
In other words, there is a new Soviet military role in the Gulf which is the direct result of the US sale of American weapons to Kuwait's enemy, Iran, from 1985 until November 1986.
Behind that, and further explaining why this seemed to be a logical move for Kuwait to make in late 1986, we must go back to 1984.
In that year, Iran was stepping up its air offensive against Arab oil shipping in the Gulf. Saudi Arabia and Kuwait jointly turned to Washington and asked to buy American weapons, particularly Stinger missiles to be used against Iranian fighter planes attacking Saudi and Kuwait oil tankers.
On May 29 President Reagan signed papers authorizing the immediate delivery of 200 Stinger missiles to Saudi Arabia, over Israeli protests. Kuwait expected also to get some of the Stingers. But on May 31, a Defense Department spokesman denied any plans to sell weapons to Kuwait, saying their needs ``might be better met elsewhere.''
The spokesman presumably had Britain and France in mind. Kuwait has bought most of its weapons in the past from them. But Kuwait did not turn to Britain and France. It turned to Moscow.
A Kuwaiti delegation flew to Moscow in July and promptly concluded an agreement for the sale to Kuwait of $327 million worth of Soviet weapons. Later in 1984, several Soviet officers visited Kuwait for ``training exercises.'' In February 1986 an ``economic cooperation agreement'' was signed between Kuwait and the USSR in Moscow.
There had been an earlier rift in US-Kuwait relations. In August 1983 the US named as its next ambassador to Kuwait Brandon H. Gore Jr., who had previously been US consul general in Jerusalem. The Kuwaitis declared Mr. Gore to be persona non grata for that reason. The US refused to name an alternate.
At that time, the whole diplomatic world knew that Israel was regularly shipping weapons to Iran. In November 1986 the whole world learned that the US was also sending arms to Iran. If the US was siding with Iran, alongside Israel, and had already refused to sell weapons to Kuwait, what was Kuwait to do for its own defense?
In world affairs one move provokes a countermove. The United States refusal to sell Stingers to Kuwait, followed by sale of weapons to Iran, caused the Kuwaitis to turn to Moscow. That has brought Soviet tankers and patrol vessels into the Gulf, which Washington did not intend, and certainly does not like.
In a well-run foreign office, the countermoves are anticipated before the moves are made.