[SecondAmendment]

Untrue. Only the Atlas V uses Russian engines. Delta IV and the SpaceX systems do not.

Okay, the SpaceX does not, but I was pretty sure the latest Delta's did use Russian engines: Lawmakers propose U.S. alternative to Russian engine

[tony549]

The Delta uses rocket engines manufactured here in the USA by Aerojet Rocketdyne; the RS-68 and the RL-10 engines.