You just came out of left field there. Lets not forget that Russia experienced a costly Civil War and two World Wars from 1914 on, one of which involved the seige of their capital city Moscow, while the United States has not fought a war on our soil since 1865. You'd be suprised how much a war, ie your cities being totally leveled, has an effect on your economy. Not to mention the United States happily rebuilding their allies economy while the Soviet Union was with held from those funds (if my history serves me right it was initially voluntary for Stalin's reasons of pride).
There are many other localized factors here the countries you mentioned, specifally America had easily accesible oil in Texas while the USSR has hard to get oil in frozen Siberia. Saudi Arabia has easy to access oil, which is the sole reason their GDP is greater than that of some of their neigbors, such as Egypt.
The only difference in efficiency between a command an market economy is who makes the best decision. A private company can invest in a ten billion dollar space hotel and lose their ass. Obviously, the business in a market economy has more incentive than the government to make the better economic decision, though I fail to see how a form of communism where workers owned the production (and elected a president to run the company) would cause them to make economic decisions different than that of a private business.
