Could it be that its neighbors in the Middle East are finally running out of patience with fanatical, obstreperous Iran?

That possibility is raised by Saudi Arabia's decision this week to severe diplomatic relations with Iran and the likelihood of Kuwait and Bahrain following suit.What's remarkable about this deci- sion is not that Saudi Arabia started trying to isolate such a difficult and dangerous neighbor but that it took so long to do so.

After all, the two countries have been trading insults and accusations almost every day for nearly a year now. Relations between the two Moslem nations have been strained since riots at the annual pilgrimage to Mecca last year killed more than 400 people.

Since then, the Iranians have attacked Saudi commercial ships in the Persian Gulf, raided the Saudi embassy in Tehran and killed a Saudi diplomat, and blown up several oil fa cilities in the eastern region of Saudi Arabia.

Clearly, the Saudis had more than enough provocation for their decision to sever diplomatic relations. But this move isn't enough. The many other Arab nations that support Iraq in its war with Iran need to follow the Saudi example.

More important, responsible na- tions around the world need to stop doing business with Iran. Iran couldn't keep fighting without the oil revenues that finance its war effort. In view of the present world glut, it should be easy for nations that buy oil from Iran to find supplies elsewhere.