Soviets sold/gave them to client states. We either obtained them from client states after they soured on the Soviet relationship or were brought by defectors.

Red Eagles is a good read on the subject.

Book: http://www.amazon.com/Red-Eagles-Americas-General-Aviation/dp/1846039703

Sweet, need another read for my Kindle. Thanks for the suggestion!

After loads of reading on the bus to work every day, here follows my reading list for military aviation:

Modern

• Viper Pilot - memoir of an F-16 Wild Weasel pilot who flew in both Iraq Wars
  
• A Nightmare's Prayer - memoir of a Marine Harrier Pilot flying out of Bagram.
  
• Warthog - Story of the A-10C pilots and their many varied missions in Desert Storm
  
• Hornets over Kuwait - Memoir of a Marine F/A-18 pilot during Desert Storm
  
• Strike Eagle - Story of the brand new F-15C Strike Eagle pilots and their time in Desert Storm
  
  

  Vietnam
  

• The Hunter Killers - look at the very first Wild Weasels, their inception, early development, successes, and failures
  
• Low Level Hell - memoir of an OH-6 Air Cav pilot
  
  

  WWII
  

• Unsung Eagles - various snapshots of the less well-known but arguably more impactful pilots and their missions during WWII (pilot who flew channel rescue in a P-47, morale demonstration pilot, etc.)
  
• Stuka Pilot - memoir of the most prolific aviator of Nazi Germany (and an unapologetic Nazi) who killed hundreds of tanks with his cannon-armed Stuka
  
• The First Team - more academic historical look at the first US Naval Aviators in WWII
  
  
  

  Overall/Other
  

• Skunk Works - memoir of Ben Rich, head of Lockeed's top secret internal firm and his time working on the U-2, SR-71, and F-117 including anecdotes from pilots of all 3 and accounts of these remarkable planes' exploits.
  
• Lords of the Sky - ambitious attempt to chronicle the rise and evolution of the "fighter pilot" from WWI to the modern day
  
• Red Eagles: America's Secret MiGs - the story of the long-top secret group of pilots who evaluated and flew captured Soviet aircraft against US pilots to train them against these unknown foes.
  
• Blind Man's Bluff: The Untold Story of American Submarine Espionage - story of the US submarine fleet starting at the outbreak of the Cold War and their exploits
  
  
  
  

  Bonus non-military aviation
  

  I highly second the recommendations of Snow Crash, Cryptonomicon, and Diamond Age. I would also recommend:
  
  

• Neuromancer - defined the cyberpunk genre
  
• Ghost in the Wires - memoir of prolific hacker Kevin Mitnick
  
• Starship Troopers - nothing like the movie
  
• The Martian - fantastic read
  
• Heir to the Empire - first of the Star Wars Thrawn Trilogy and the book that arguably sparked the growth of the Extended Universe of Star Wars
  
• Devil in the White City - semi-fictional (mostly non-fiction) account of a serial killer who created an entire palace to capture and kill his prey during the Chicago World's Fair
  
• Good Omens - dark comedy story of a demon and an angel trying to stop the end of the world because they like us too much
  
• American Gods - fantastic story about how the old gods still walk among us
  
• Dune - just read it
  

https://www.amazon.com/Red-Eagles-Americas-General-Aviation/dp/1846039703

If you're the reading type, I would suggest Steve Davies' "Red Eagles" in which he discusses just that. We often got them from countries that had previous Soviet influence, or from allies that captured them previously (if I remember correctly, one of our first batches of MiG-17s came from Israel).

Davies' book reads rather easily, and contains great primary sources. I suggest grabbing a copy!