Original sentence: He was an anti-communist who negotiated arms reductions with the Soviets; his policies are sometimes credited with accelerating the demise of the Soviet Union.His administration was also well known for the Iran-Contra Affair, where members of his administration exchanged arms with Iran for hostages and used the proceeds to fund the Contras, a para-military, anti-leftist group in Nicaragua
Edited sentence: He played a decisive role in winning the Cold War and thus moved the United States into its current position as the single remaining superpower in the world.He was an anti-communist who negotiated arms reductions with the Soviets.His administration was also  known for the Iran-Contra Affair, where members of his administration exchanged arms with Iran for hostages and used the proceeds to fund the Contras, a para-military, anti-leftist group in Nicaragua