Sputnik spoke with veteran Russian military analyst Alexei Leonkov to explain the meaning of President Vladimir Putin’s May 6 announcement that Russia would be testing its tactical nuclear forces. Leonkov said that “Exercises using this kind of ammunition were last conducted during the Soviet period. Therefore, it’s necessary to carry out drills so that those who would have to use them know how to handle and use these weapons.” Sputnik added: “Put another way, the exercises are designed to serve as a message from Russia that `there is a limit’ to the aggression Moscow is willing to tolerate, Leonkov emphasized. `But before this there was his statement [in March] about F-16 aircraft based in NATO countries participating in hostilities on the territory of Ukraine, and that it doesn’t matter who’s flying them—Ukrainian or non-Ukrainian pilots—that [Russia] will consider the matter of airfields where these aircraft are based and take off from, that they will become our legitimate targets. But apparently, this warning by our president was not heard in the West,’ Leonkov explained.