Defense Secretary Jim Mattis and Secretary of State Rex Tillerson arrive on Capitol Hill, August 2, 2017.
At the time, President Donald Trump wanted to withdraw from the deal, claiming Iran had violated the terms.
Others, including then-Secretary of State Rex Tillerson, pushed back, citing a lack of evidence of any violation.
Russia, Woodward then notes,"had privately warned Mattis that if there was a war in the Baltics, Russia would not hesitate to use tactical nuclear weapons against NATO.".
Some experts prefer the term "non-strategic nuclear weapons," as the use of nuclear weapons would have both tactical and strategic implications.
Russia and the US have more than 90% of the world's nuclear warheads, though Russia's arsenal is slightly larger.
"It would lose, and as a result of that, they have placed more emphasis on more usage of tactical nuclear weapons as a leveler. »