Founded in 1961, the Defense Intelligence Agency (DIA) has gotten bigger and bigger over time, with a focus principally on whatever wars the US happens to be fighting at the time, and the ones they might be fighting soon.
That seems laughably simplistic to the modern Pentagon, because of course the US is fighting across the entire planet, all the time, and near as anyone can tell forever. With that new global theater of operation in mind, Pentagon planners are seeking a massive increase in size for the DIA.
“The is a major adjustment for national security,” noted DIA director Lt. Gen. Michael Flynn, and indeed the indications are that the long term goal is to make the DIA rival the size and scope of the CIA.
With the CIA well into a plan to downplay the whole “espionage” thing in favor of assassinations, moving into the Pentagon’s turf of killing people abroad, it was perhaps inevitable that the Pentagon would respond by encroaching on CIA territory. In the end, this sort of “competition” could continue for quite some time, since both CIA and Pentagon can rely on massive budgets for the foreseeable future.