My admittedly more cynical reason is that it keeps the overall defense budget at high levels, while diminishing under the covers, funds available for weapons, ammo, operations, boats/planes/vehicles... ie, anything actually related to defense.
You are probably right, but I have seen stories where they basically were saying the US military was planning for problems caused by “global warming”... this is despite the fact that satellite data shows that there has been none for 18 years or more.