Our daddy is fighting at the front for you - Back him up - Buy a United States Gov't Bond of the 2nd Liberty Loan of 1917 - Dewey" poster
The pattern
This still is filed under Donor guilt appeal.
Define
The donor is asked to feel the cost of not giving, then given a precise act that relieves it.
Mechanism
Obligation then release. Close kin to problem-agitate-solve, aimed at a gift rather than a purchase. Handle with care.
Verdict
The need is real, the ask is specific, and the donor can act today.
Why it works
It uses guilt and obligation. By putting the appeal in the mouths of innocent children whose father is risking his life 'for You', it makes refusing to buy a bond seem like a betrayal of both the soldiers and their families.
Steal this when
You need to motivate action by highlighting the sacrifices others are making on the audience's behalf.