Well differences apart, USA military equipment is still most reliable and modern in the world far ahead of what China and Russia are producing. Gulf countries from day one have not focused on developing military themselves rather they still rely on USA for all there defense. USA is in every gulf country for there defense like Doha, Kuwait, KSA. You cant just have a strong defense by buying expensive weapons from west, it takes years of hard work and indigenization.
Not quite sure about that. Recently Russia has been able to produce quality defense equipment at fraction of the price that the Americans pay for their equipment. One good example is that of the S-500 air defense system. It is cheaper than the American Patriot system, and much more inexpensive. The same can be said about the ICBMs as well. SS-18 Satan remains the most powerful ballistic missile manufactured till date. And I believe that Russia has also won the competition for the fifth-generation fighter aircraft. The Sukhoi Su-57 is rumored to be much more capable when compared to Lockheed Martin F-35 Lightning II.