If it will keep Biden in blood money, Ukraine will call up 100 year olds.
On occasion, we have brought in the old, for example, the medical field with doctors and dentists in their 60s, there are many fields where age is not a barrier, computers, intelligence analysts, field grade officers, specialized technicians/scientists, engineers, whatever.
When your nation is actually being invaded and your cities overrun by the enemy some peacetime luxuries are not indulged, after 9/11 even the United States was bringing in old ex-Green Berets and allowing 42-year-old women and men their first enlistment.
I bumped into Rear Admiral Grace Hopper at the airport once when I was heading to a NATO exercise, she retired in 1986, months away from her 80th birthday.