In his Boston Globe editorial, columnist Jeff Jacoby proposes a single solution to two problems: let immigrants serve in the military and gain a fast path to citizenship.
He notes that one in five union soldiers in the Civil War was an Irish immigrant. I believe that the Irish immigrants were forced into service in a sort of indentured servitude by not being able to buy their way out for $300, so that may be a bad example; but the thought of letting prospective citizens earn their citizenship through military service has some merit.
While the languange may be a barrier it may also be a benefit in a world of shifting global requirements. Security concerns may require some limitations. It would certainly be more palatable than a draft.
Liberals will argue against this, probably yelling “cannon fodder” and arguing this influx of foreign soldiers will simply encourage the use of the military or something along those lines.
This also kinda reminds me of Starship Troopers where suffrage only belongs to discharged veterans of the military. I hope this doesn’t happen in the future, but it seems to be a plausible solution in dire times.