Reagan and Gorbachev Agreed to Pause the Cold War in Case of an Alien Invasion

Which I suppose is a good thing.  Here's the story:

At one point during the 1985 Geneva Summit, President Ronald Reagan and Soviet Premier Mikhail Gorbachev took a break from negotiations to take a walk. Only their private interpreters were present and for years, the details of what they talked about were kept secret from both the Russian and American public. But during a 2009 interview with Charlie Rose and Reagan’s Secretary of State George Shultz, Gorbachev revealed that Reagan asked him point-blank if they could set aside their differences in case the world was invaded by aliens.

As Jimmy Orr reported for the Christian Science Monitor at the time:

Shultz was talking about the Lake Geneva summit and mentioned the two leaders ducked out of a meeting to take a walk to a nearby cabin.

"I wasn't there...," Shultz said before Gorbachev cut him off.

"From the fireside house, President Reagan suddenly said to me, 'What would you do if the United States were suddenly attacked by someone from outer space? Would you help us?'

"I said, 'No doubt about it.'"

"He said, 'We too.'"

"So that's interesting," Gorbachev said to much laughter.

Both sides actually thought about, and actually implemented, possible space weapons, although certainly they intended to use them against each other.

During the 1950s and ‘60s, a group of U.S. Army engineers was tasked with thinking up theoretical weapons that could be used to defend non-existent lunar bases. And recently, Anatoly Zak reports for Popular Mechanics, the Russian government revealed that in the 1970s, the Soviet Almaz space station was not only armed with a top-secret space cannon, but it was also test-fired.

Between the two of them, at least there was something we could use against space aliens.