The 1987 Intermediate Nuclear Forces (INF) Treaty between the United States and the then-Soviet Union was designed to eliminate offensive nuclear-armed and conventional missiles.
The treaty does not touch on the creation and deployment of anti-ballistic missile defense systems such as one deployed by the U.S. in Romania in May 2016 and another planned for installation in Poland.
The U.S. Congressional Research Service said in a report on February 24, 2016: “Because the INF Treaty defined treaty-limited ballistic missiles and cruise missiles as ‘weapons delivery vehicles,’ rockets that were not designed or tested as weapons-delivery vehicles were not banned by the treaty...The INF Treaty also did not ban the possession or testing and production of missile defense interceptors.”
The United States says that the missile defense system in Romania is intended to prevent states such as Iran from launching missile attacks on other nations. U.S. Deputy Defense Secretary Robert Work said at the May 12, 2016 activation of the Romanian missile defense facility, "As long as Iran continues to develop and deploy ballistic missiles, the United States will work with its allies to defend NATO.” Work told a news conference that the shield would not be used against any future Russian missile threat: "There are no plans at all to do that."
And if the U.S. were to change the defense system into an offensive one, the world would certainly take notice, experts say.
RAND Corporation senior political scientist Stephen Flanagan told Polygraph.info in an October 25, 2016 e-mail: “The Russians have contended that because the launcher for the Aegis ashore missile is ‘practically identical’ to a system used aboard Aegis warships that is capable of launching Tomahawk cruise missiles, it therefore violates the INF Treaty, which bans the deployment of land-based cruise and ballistic missiles with a range from 300 to 3,400 miles.
“The Russians also contend that the SM-3 interceptor missile could be fitted with a third stage and made into a long range offensive missile (in violation of INF) or given additional capabilities and made into a ballistic missile system capable of countering Russian ICBMs," he wrote.
“U.S. officials have made clear there are no Tomahawk missiles at the site in Romania, and have gone to great pains to demonstrate to Russia that the U.S. has ‘no plans at all’ to strengthen the European Phased Adaptive Approach missile defense system to counter Russian ballistic missiles," Flanagan wrote.