Is the Middle East a lucrative marketplace for Russia and USA weapons? Is business of selling weapons thriving there?

Russia is the second biggest arms dealer after the U.S. Russia has no need to buy in the Middle East where they have mainly American weapons. Thats why terrorists have them.

The US recently sold $80 billion worth of aircraft, weapons and bombs to Saudi Arabia to use in Yemen. Now there are 20 million people there in need of humanitarian aid because the Saudis have bombed the country to pieces.
War is big business.

What with the oil money slushing around, and the incessant political turmoil, I'd imagine it to be the center of the gun-running trade.