On December 14, the United States issued a series of sanctions on a Turkey's defense industry. The package of sanctions within the CAATSA program signifies another round F-35 / S-400 tensions between Turkey and the United States.

Although military-technical factors have been highlighted as the main reasons for the sanctions, they also bear serious geopolitical implications. By this move, U.S. government issued its first serious warning to Ankara, which had been building its foreign policy on the basis of the American-Russian competition in recent years. Since the last years of the Obama administration, Ankara has been trying to shape its relations with the United States in the context the of "rapprochement with Russia” threat. Yet, U.S. government indicates that it can take serious steps against this threat, and signals that the sanctions could possibly be extended to Turkey's economic sphere. Thus, the Americans want Turkey to clarify its relations with the United States and Russia. 

Another important dimension of the package is the warning to other U.S. allies, especially the Gulf monarchies, Egypt, India, Pakistan and South Korea, which have been expressed interest in acquiring the S-400 system. By imposing sanctions on a strategically important ally such as Turkey, the United States is sending a serious message to those countries, which want to build military cooperation with Russia and seek balance between the United States and Russia.