Writing in The New York Times, the Republican political-science professor points out that the key sentence in the treaty is this: "The United States will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the Nuclear Nonproliferation Treaty and in compliance with their nuclear nonproliferation obligations." [emphasis added] That still leaves the United States able, explains Feaver, "to use nuclear weapons against nuclear states that are party to the Nuclear Nonproliferation Treaty--read: Russia and China." Plus, it may use those weapons against non-state actors like al-Qaeda, against states who haven't signed the nonproliferation treaty, and against states that "are in violation of the treaty, a list that includes Iran, North Korea, and Syria." There's more: "Crucially, since the new policy does not delineate what it means for states to be 'in compliance' with the nonproliferation treaty, the United States has a major loophole."
Finally, this new policy even leaves room for adjustment as advances are made in biological weaponry. Feaver's bottom line:
The administration claims this new declaration will create strong incentives for states to eschew nuclear weapons. Critics, many of them my fellow Republicans, claim it substantially weakens America’s deterrence against attacks with non-nuclear weapons of mass destruction. My view is that the new policy buys a trivial new incentive at the cost of a modest loss in deterrence. Reasonable people can disagree as to whether the bargain is worth it, but it is a bargain on the margins.