States wishing to leave the Union should be required to reimburse the Federal government in full for infrastructure and other expenditures made by the Federal government for the use of the state's citizens prior to leaving the Union.
These expenses were done for the support of United States citizens and should have to be reimbursed. As a side effect the reduction in required defense, social, and infrastructure spending, as well as reimbursements would go a long way into alleviating the national debt.
To do otherwise would not be fair and equal to those that remain with the Union.