Identify an arbitrator both you and he trust.
Both of you need to understand, you must reach an agreement or commit to handing $10,000 to the attorney's.
Isn't that sufficient incentive to find an agreeable solution?
You repeatedly used the word FORCE. You would be well advised to take arbitration action before this escalates to true adversarial, burnt earth, retaliatory, ego driven degeneration of a relationship..