Actually, I would as well. You have Soldiers, Sailors, Marines, and Airmen who are going out into combat with no guarantee that they will make it home so of course I am sympathetic to this but there may be some issues when they do return home and affiliate (as they should) with a local congregation. Perhaps the Didache was addressing some of the difficulties of their time (I.E., rampant persecution)? The practice of "Transfer by letter" I believe comes from the Pauline epistles where Paul "commends" people to other congregations that they should be "received" upon their arrival.Well, they're ordained by someone, and thus licensed to work in their name. Since they also carry out church functions in the field and on the base, I think the definition of a church (in the sense of something like a local assembly) can be a bit more generous than the private organizations that meet in your neighbourhood.
I'd probably extend servicemen a bit of liberty if they're in an active combat zone and want to be baptized. They might not know when they're getting back to the baptistry at First Baptist Church of Midwest, USA--if ever. It's public, Trinitarian, done with water, administered to a confessing believer by a duly ordained minister of a Christian church. Perhaps not ideal circumstances, but good enough.
As far as military chaplains are concerned, I understand that they are ordained and that they are, in fact, tasked with conducting religious services and the ecclesiastical structure gets things convoluted here as we try to flesh through everything here! According to the Roman Catholic Church, the Church is "Wherever the Bishop is" (of which I adamantly disagree) so the authority to baptize and administer the Sacraments (Communion, etc.) is conferred upon the priests and bishops under the guise of "Apostolic Succession." This means that a military chaplain who is a Catholic priest can administer a legitimate baptism that is recognized by Roman Catholics worldwide. Most Protestant denominations acknowledge their baptisms as being "Universal" (small c "catholic") in nature and therefore one's authority to baptize is according to ordination credentials, synods, presbyteries, etc. which extend outside of the local congregation. Herein lies the problem with Baptists who do not acknowledge any authority beyond a local Church congregation!
There are Baptist Chaplains in the military but if they truly are "Baptist," wherein is their authority to baptize? Baptist preachers are licensed, ordained, and sent out as evangelists and missionaries operating under the authority of their respective home church and in such cases, they are authorized to baptize under the authority of their sending church usually with the intent to plant new churches or whatever. I guess we could say that whoever this Baptist Chaplain baptizes during a combat deployment may be techncally considered as a member of this Chaplain's home church until they ultimately affiliate with a congregation of their own? I am guessing that this Baptist Chaplain could provide a certificate or an official letter or something stating the conditions of the baptism, and that the prospective congregation could receive this person under such conditions? I think I would much prefer this than to require them to be "Baptized Again" because the authority of their baptism was in question.
Perhaps I am overthinking things but this is a legitimate issue is it not?