How Trump's nuclear posture addresses new global threats

If the 2010 nuclear posture review (NPR) reflected a left-of-center compromise, probably to the right of President Obama’s preferences, the 2018 NPR is right-of-center, yet falls to the left of many of President Trump’s statements. While staying within the policy mainstream and containing considerable continuity with its predecessor, Trump's review does make a few notable departures.

Some key changes:

• Consideration of additional sea-launched capabilities with lower-yield warheads
• Inclusion of more than 30 references to nuclear weapons deterring non-nuclear attacks
• Decreased emphasis on U.S. global leadership of the nuclear nonproliferation regime

Yes, but: The most important difference may not be in the report’s pages, but in Trump's increasing emphasis on nuclear weapons as an instrument of national power, particularly in a more complicated international threat environment.

Why it matters: Trump’s heated rhetoric bears little resemblance to the more measured declaratory policies in the formal documents. The president commands the nuclear forces and bears the sole burden of authorizing their use should deterrence fail. In communicating U.S. policy, it's his words that matter most.

Go deeper: An extended take at Defense360.

Rebecca Hersman is the director of the Project on Nuclear Issues and a senior adviser in the International Security Program at the Center for Strategic and International Studies.