Retirement is not alimony. It was once considered that way, and once deductible (and easier to process). Retirement is a division of property if I recall correctly. The only trick is if you don't meet the 10/10 rule, DFAS doesn't handle the money and issue the 1099s. If no 1099s, the retiree should keep receipts of paying the spouse and subtract the amount paid, i.e., negative income. On that line of the return you can say "Military retirement pay to ex-spouse {name, SSN} per USFSPA." And of course inform the ex spouse of what they owe taxes on.
