The lengthy war between Iran and Iraq has brought to the fore a border dispute between Iraq and this country, renewing tension between the two Arab states that are supposed to be allies.

In mid-November, Kuwaiti Prime Minister Saad Sabah made a secret trip to Baghdad to try to resolve the issue after Iraqi forces crossed the disputed border and briefly occupied a strip of contested land. He reportedly made no progress. Subsequently, Kuwait installed antiaircraft guns and missile launchers on one of the two islands off its coast that Iraq has long coveted and regards as crucial protection against a seaborne Iranian attack on its port, Basra, from the sea.

At the same time, the Kuwaiti government is planning to complete a network of roads and bridges to link the marshy islands, Bubiyan and Warbah, to the mainland, thereby reaffirming its sovereignty claim. Iraq has repeatedly asked to "lease" the islands from Kuwait, but the government here has rejected the requests, apparently fearing that once the Iraqis are installed they will never leave.

The renewed tension over the border issue came just as Kuwait was hosting a summit of the Arab Gulf Cooperation Council, whose six members agreed to set up a rapid deployment force to protect against any outside aggressor.

The main concern is clearly the military threat from Iran. But the unresolved Iraqi-Kuwaiti border issue serves as a reminder that there are intra-Arab disputes in this region as well.

The issue of the islands is part of a larger border dispute stemming from Iraq's refusal, in 1961, to recognize Kuwait after its independence from Britain. Iraq laid claim to Kuwait's territory then and sent its Army across the border.

Britain, and later the Arab League, came to Kuwait's rescue, sending troops to face down the invading Iraqi force, which withdrew.

Two years later, Iraq recognized Kuwait's independence, but the two states are still wrangling over the demarcation of the border. Part of the problem lies in the fact that the Arab League force set up a line of defense slightly to the north of the old international border.

It is still not clear why Prime Minister and heir-apparent Saad decided to broach the contentious border issue in mid-November, just before the Persian Gulf Cooperation Council met.

His decision to go to Baghdad on a secret three-day visit that ended Nov. 13 was apparently controversial even inside the ruling Sabah family. Western diplomats and Kuwaiti analysts note that Kuwait's foreign minister, Sabah Ahmad Jabir, did not go with the prime minister, and it is reported that he regarded the visit as ill-advised.

The islands of Bubiyan and Warbah have taken on increased strategic importance because of Iraqi concern that the Iranians might try to outflank Iraqi forces positioned north and east of Basra, land on the islands and march northward on Basra.

The Iraqis have set up a base for military hydrofoils on a river just a few miles northwest of Warba Island, according to western diplomatic sources.

The islands are uninhabited and almost entirely marshland, making such an operation difficult. One western diplomat dismissed the idea as "laughable" and far beyond Iran's logistical capabilities.

Still, the Iranians chose precisely this kind of terrain to penetrate successfully into Iraq northwest of Basra last February. Indeed, they came through the biggest marshlands of southeastern Iraq, seized the Majnoon islands -- which were created by the Iraqis through swamp drainage -- and reached the strategic Baghdad-Basra highway. Iran still holds most of the two islands.

The Kuwaitis are going ahead with the construction of a road and bridges to connect both Bubiyan and Warbah to the mainland. A first bridge linking the southern end of Bubiyan is completed, and the French have built a water-resistant roadbed along the marshy southern and eastern coast facing Iran.