"The sole purpose of our nuclear arsenal should be to deter nuclear attack against the United States, our allies and partners," the letter signed by 16 senators said on Monday. "However, the reported policies outlined in your forthcoming Nuclear Posture Review increase the risk of a nuclear arms race and raise the real possibility of nuclear conflict."
The senators noted in the letter that the $1.7 trillion cost to modernize the US nuclear triad would siphon off funding needed to upgrade and maintain conventional forces.
They also chastised Trump for ignoring the 1968 Non-Proliferation Treaty's requirement to strive for nuclear disarmament.
The letter was signed by 16 senators including Dianne Feinstein and Bernie Sanders.