Russia poses increased nuclear threat to NATO.

• Author: Tadjdeh, Yasmin
• Position: Global Defense

The United States and its NATO allies face a growing risk of nuclear conflict with Russia, one expert recently said.

"The U.S. certainly faces a nuclear landscape that is very complex, uncertain and with a great deal of risk," said retired Marine Corps Col. Guy B. Roberts, who previously served as deputy assistant secretary-general for weapons of mass destruction policy and director of the nuclear policy planning directorate for NATO.

Roberts--who now works as an independent consultant on national security and nuclear proliferation--said since he left NATO in 2011, there has been a dramatic change in the security environment.

In 2010, the alliance "characterized the NATO-Russia relationship as a strong and constructive partnership based on mutual confidence, transparency and predictability. That is no longer the case," he said during a recent panel discussion at the American Security Project, a Washington, D.C.-based think tank.

The Cold War foe has since illegally annexed Crimea, reportedly attempted to influence the 2016 presidential election and built up its nuclear capabilities.

In addition to Russia, the alliance also needs to be cognizant of the threat of nuclear attack by other states such as China, and the potential use of weapons of mass destruction by terrorists or non-state actors, Roberts said.

The United States currently maintains non-strategic nuclear weapons in Europe and "the emphasis now... is to enhance that capability as part of the overall NATO defense posture," he said.

That presence plays a "vital assurance role" for U.S. allies and it deters adversaries, he added.

It will be increasingly important for NATO alliance members to share the burden with the United States, he said.

"The fact is that our NATO allies participate in the nuclear mission," Roberts said. "Up to 16 nations... could potentially fly the mission with what we call dual-capable aircraft, which are currently primarily...