The rulebook that limited US and Russian nukes has fallen apart. Both sides could revert to worst-case scenario planning, experts warn.

Fuente: Business Insider

New START expired this week, prompting a new era without a nuclear arms deal between the US and Russia. Mikhail Svetlov/Getty ImagesThe US and Russia's New START nuclear treaty expired this week. No further deal has been reached, opening the door to a larger nuclear threat.