Mexicans are famous for their hospitality toward visitors, whether rich gringo tourists or down-at-the-heel political exiles. But the obliging attitude the Mexican government has shown to thousands of uninvited, troublesome "visitors" along the southern border with Guatemala is unusual even by Mexican standards.

Since 1981, Mexico has pursued an evenhanded "live and let die" policy toward leftist Guatemalan guerrillas who seek refuge in Mexico -- and toward the Guatemalan military's periodic punitive expeditions across the border.

With its relatively small Army, Mexico is always anxious to avoid direct confrontations that could lead to military action. So it turns a blind eye to guerrillas who were infiltrating southern Mexican states, along with thousands of Guatemalan Indian peasants fleeing chaos in their homeland.

The "strategy of accommodation" continues, but with an important condition extracted from the guerrillas in return for freedom from harassment: The leftist rebels must do nothing to stir up trouble for their reluctant hosts.

Mexico's appeasement policy is described in a special analysis by a CIA official, who classified it "Secret Noforn Nocontract Orcon" -- meaning no one may see it without permission from the official himself. That includes friendly intelligence services and American CIA contractors.

"Although we assume that Guatemalan guerrillas do use the border area for safe haven, resupply and arms smuggling, our knowledge of the actual extent of arms smuggling and other related activities remains very vague," the report acknowledged. It added: "Because of the convenience offered by the relatively unguarded border for guerrilla activities against Guatemala, as well as Mexico City's good foreign relations with the Cuban mentors of the Guatemalan insurgents, we believe that the guerrillas are unlikely to jeopardize their position by undertaking either military or subversive activities against Mexico itself."

The report then describes the "open border" policy: "Mexico City apparently has decided that the best strategy to deal with the guerrilla presence along the border, and resulting raids on Mexican territory by Guatemalan security forces, is to monitor the situation while avoiding confrontation . . . . The Mexican Army has been instructed to maintain a minimal presence along the border and not patrol extensively.

"Given the potential for violence, this strategy of accommodation presently seems to benefit stability while not endangering Mexico's principal security concerns. Should Mexico City receive evidence that the guerrillas are . . . undertaking . . . threatening activity against Mexican interests, we would expect a major, speedy change in policy."

Meanwhile, the CIA report notes, earlier fears that the flood of refugees -- 38,677 by official Mexican government count -- would prove seriously disruptive have not been borne out. "The vast majority appear to be apolitical Indian peasants," the CIA report states. "The feared spread of subversive ideas . . . does not appear to be materializing."

The "strategy of accommodation" seems to be working.