Carter insisted that what he termed "Soviet aggression" could not be viewed as an isolated event of limited geographical importance but had to be contested as a potential threat to US influence in the Persian Gulf region. The US was also worried about the USSR gaining access to the Indian Ocean by coming to an arrangement with Pakistan. The Soviet air base outside of Kandahar was only thirty minutes flying time by strike aircraft or naval bomber to the Persian Gulf. It "became the heart of the southernmost concentration of Soviet soldier" in the 300-year history of Russian expansion in central Asia.