A SMALL slogan chiseled into a desolate mountainside on the Soviet-Iranian border near here calls on frontier troops "to protect the motherland."It appears the border guards have carried out their duty well in Turkmenia, which is still firmly in the control of hard-line Communists. The arid republic, reportedly the poorest in the former Soviet Union, hasn't experienced the ethnic tension that has shaken the other Central Asian republics. And few worry about the rise of Islam, despite Iran's proximity to the south. "It's the nature of the Turkmen character. We like stability," says Alexander Dodonov, the second secretary of the republic's Communist Party. He adds that despite Turkmenia's declaration of independence last month, there is a strong allegiance to Marxist/Leninist principles. "There's real love for Lenin here," he says. "The Soviet system gave the Turkmen people their own state. Before Turkmens never had their own state and were discriminated against. Now, they're not." Ethnic Turkmens comprise about 71 percent of the republic's 3.2 million inhabitants. Russians and Uzbeks are the other predominant nationalities, and many say they are made to feel welcome. "The Turkmens understand the Russians and Russians understand the Turkmens," says construction worker Igor Sokolov. "We are all working together to build a better place to live." Ashkhabad, the capital, is bordered by the Kara Kum desert to the north and the Kopet mountains to the south. Few luxuries grace this city, but its people say they have the basics, such as bread, milk, butter, and cheese - items that have become scare even in Moscow. Given the stable living conditions, officials in Turkmenia say they are not concerned the growth of Islam in the region will turn toward fundamentalism. "We are even widening contact with Iran," says Mr. Dodonov. "We've opened a border crossing. It's the first step on the path to closer relations and development." Though relative calm prevails, an ongoing dispute with neighboring Uzbekistan over water use from the Amu-Darya River on the border between Turkmenia and Uzkbekistan has the potential to intensify. The two republics have squabbled over the use of its water resources for extensive irrigation projects.