Moscow, Berlin, St. Petersburg, Beijing.

They're all tourist destinations and thriving cities, but in an alternate universe, those cities could have been wiped off the map in a nuclear holocaust, newly declassified documents from the U.S. military revealed. The documents list hundreds of sites that would have been targets in the event the U.S.-Soviet Cold War became a nuclear war, The New York Times reported.

The never-before-seen list was released on Dec. 22 by the National Archives and Records Administration. The list, part of an 800-page document, was made public in response to a records request by the National Security Archive, a nonprofit affiliated with George Washington University. It took nine years for the government to respond to the records request.

ADVERTISEMENT Thanks for watching! Visit Website

The most chilling targets are those tagged as population centers -- cities that had large civilian populations, but weren't of much strategic value to American forces.

“It’s disturbing, for sure, to see the population centers targeted,” William Burr, a senior analyst at the National Security Archive, told The New York Times.

"Their target priorities and nuclear bombing tactics would expose nearby civilians and 'friendly forces and people' to high levels of deadly radioactive fallout," Burr wrote in an analysis of the Strategic Air Command documents, CNN reported.

ADVERTISEMENT Thanks for watching! Visit Website

ADVERTISEMENT Thanks for watching! Visit Website

Other targets included airfields, military installations and industrial centers. Each target was dubbed a "Designated Ground Zero" by Strategic Air Command, a Department of Defense command that controlled most U.S. nuclear assets during the Cold War.

The overall strategy was to cripple the Soviet Union's ability to respond to a nuclear strike by prioritizing air fields, defensive positions, and industrial infrastructure necessary for manufacturing and maintaining Soviet aircraft, analysts said. Secondary targets included electric grids, dams and railroads.

The document's official name is “Atomic Weapons Requirements Study for 1959." It was drawn up in 1956 by the Strategic Air Command during a time of increasing anxiety over the Soviet Union and the Cold War.

Despite the extensive target list -- and the clinical references to population centers marked as targets -- President Dwight D. Eisenhower ordered the military to reduce its nuclear stockpile tonnage by half, The New York Times reported.

“He just thought this would lead to the annihilation of the human species,” Alex Wellerstein, a historian of nuclear weapons at the Stevens Institute of Technology in Hoboken, told The New York Times.

Although he called the list "grim and frankly appalling," nuclear weapons expert Stephen I. Schwartz said he believes it will serve as a reminder of the destructive power of nuclear weapons, and the reasons why they've only been used twice in the history of modern combat.

“We’ve known the general contours of nuclear war planning for a few decades,” Schwartz said, per The New York Times. “But it’s great that the details are coming out. These are extraordinary weapons, capable of incredible destruction. And this document may be history, but unfortunately the weapons are not yet history.”

Sources: The New York Times, The National Security Archive at George Washington University, CNN / Photo source: National Security Archive