Two men stand in a pool of gasoline. One man has 20 matches one has 5.

The man with five matches gives up his matches under the promise that the man with 20 matches won't hit him. A couple other men with matches at the edge of the pool of gasoline promise to uphold this agreement.

20 years later the man with 20 matches takes the man who now has no matches' arm. All the signatories let it slide because the man with 20 matches had a decent claim to the elbow. 10 years after that, the man with 20 matches tries to take the entirety of the man with no matches; the men with matches on the edge of the pool are afraid to do anything less matches get thrown back at them.