Dual citizenship
Could have two passports?
There are things he could do to assure his money actually goes to his kids instead of his ex-wife's new boyfriend's boat.
Trust funds, escrows, etc… Giving your ex a court ordered blank check every month is never spent on the kiddies.
A lot better option than hiding out in Dubai until your passport expires. Then what is your end game?
DNA tests maybe? Those kiddies could be any bloke's in Silicon.