Inside Report (2)

A little-reported mini-cold war is under way between the US and the Soviet Union.

Both sides are restricting the exchange of visitors. The latest example: Georgi Arbatov, the Kremlin's leading ''Americanologist,'' was nearly prevented recently from getting a visa to attend a meeting of an international commission on disarmament and security issues in Mount Kisco, N.Y. Arbatov got his visa at the last minute, but only after a prestigious member of the commission had intervened with the State Department. Arbatov, director of a Soviet research institute, was allowed to stay in the US only five days.

Last spring, the State Department refused to extend a visa held by Arbatov, thus preventing him from appearing on a US television program.

Asked about his visa troubles, Arbatov told the Monitor: ''I think they don't want me to talk to Americans.''