- Exclude Christmas Island from the immigration zone. - Build a base for 5 Patrol boats - Pick up boat people and transfer them to the patrol boat - Sink the temporary transport - Take them back to Indonesia and drop them off.
If Indonesia complains then surely our American "partners", you know the country that has bases here now on Australia would back us up.
Cheaper than all the rest of the solutions. Or just pay Indonesia to take them back would still be cheaper.
