Speaking from experience, the Soldier's commanding officer does not have any legal authority in this case, cannot "force" payment of rent or any other debts, and will only look after the well being of the Soldier...not the landlord. 

LOL  (sorry)You need to send Chase's Short Sale Department a "3rd Party Authorization" and request to initiate a short sale. 

With that being said,  I just read a book about buying and selling apartment complexes and one of the things discussed by the Author was business partnerships. 

Someone in this age range is more likely to take risks, not foresee consequences, not take responsibility for their actions, and tends to follow peer pressure above that of authority.

These BS authorities are nothing but a sham, but such is life.Anyhow back on track.  

They were allowed to have a trusted person view the place for them if they gave authorization in writing.

The IRS will share information with state and local taxing authorities.

The trust documents will dictate who the trustors, trustees, and beneficiaries are and what authority they have all been granted. 

However, checks from the Housing Authority (for our Section 8 tenants) come to us as electronic funds directly deposited into our account.

Doesn't sound like a lot of authority.