A Kellogg-Briand pact is no more a suicide pact than the US Constitution in 1861.
Of course it's not a suicide pact, but how could it be considered binding on people who didn't sign
it, or don't even know about its existence?
If all the people of Earth decided that resolving their differences through violence and war of any kind was unacceptable, and formalized their agreement on this one
stance through a treaty, does that automatically make the treaty binding on extraterrestrials