“Our reports showed a massive anomaly in the timespace continuum.
Timelines jumping left and right, stopping and starting…
Until suddenly, everything ends.”
I mean it just goes down to whoever uses it first, then all the others effectively never had a time machine.
I mean, depends on the specifics.
If there’s a way to detect time travel uses and the effects aren’t immediate, that is, it take some time before the actions of the past catches up to the future, then they could effectly be doing MAD across space time.
Like in Terminator, when Skynet sent back the terminators, John Connor did not immediately cease to exist. There was a moment of time for them to react and send their own protectors.
they made an entire series of documentaries about this called Command & Conquer: Red Alert.
If they all used it at the same time, there’s a possibility that it would result in 5 different alternate realities, one where each of those countries has achieved their goals. Maybe 6 different alternate realities, including the original.
War, war and more war.
Either the original timeline ends and everything is destroyed or nothing happens.
How would the present know the past changed?
They’d have to figure out how to make it teleport the subject as well. The earth isn’t in the same place today as it was yesterday, or even a minute ago.
Snake Jazz episode from Rick and Morty comes to mind
