Turkey condemned new American sanctions over its purchase of a Russian S-400 air defense system. Washington's measures target Turkey's top defense procurement and development body, saying the missile system could endanger U.S. military technology and personnel. The Turkish President called the sanctions a grave mistake and said his country may retaliate. For more analyses, Global Watch talked to Wang Jin, associate professor at Northwest University of China's Institute of Middle Eastern Studies. He said Washington's move will influence future ties between the Biden administration and Ankara.