Current Pentagon plans have its intelligence division growing by 1,600 military and civilian personnel over the next several years. It remains unclear on where that personnel increase would put DIA's total force at, since those numbers are classified.
But that additional manpower at DIA would put the agency in a position to take a direct role in conducting overt and covert U.S. intelligence operations abroad, a role traditionally reserved for operatives at CIA.
Sen. John McCainJohn McCainTrump budget to boost defense spending by B Father of slain Navy SEAL wants investigation A stronger NATO for a safer world MORE, the ranking member on the Senate Armed Services Committee, told reporters Tuesday the language was not intended to prevent the DIA expansion.
The restrictions included in the compromise defense legislation simply provides Congress the necessary oversight over DIA and the rest of the intelligence community.
That said, McCain agreed that DIA's plans to take a more active role in intelligence operations puts DOD on a "slippery slope" toward infringing upon the domain of CIA and other civilian intelligence organizations.
The last major expansion of the Pentagon's intelligence operations began in early 2000, under then Defense Secretary Donald Rumsfeld.
The former DOD chief sought to build up DIA to a point where it would essentially become the Pentagon's own in-house CIA, carrying out intelligence and surveillance operations independently.
That effort was roundly criticized by CIA proponents and others inside Washington, citing Rumsfeld's use of the bolstered DIA to backdoor CIA and other intelligence organizations during the run up to to the Iraq war.
While questions remain on whether this latest effort at DIA will suffer the same fate, Tuesday's language in the FY'13 defense bill could indicate that some on Capitol Hill remained concerned.
The limitations on DIA expansion in the FY '13 legislation came alongside language approving a $160 million increase to U.S. Special Operations Forces, "which has been a key component of the war against violent extremists," according to lawmakers.
The majority of those funds will pay for enhanced intelligence, surveillance and reconnaissance capabilities for U.S. special operations units, while "maintaining incentives for assistance against terrorism" for partner nations assisting U.S. counterterrorism operations.
U.S. and Afghan special forces, largely backed up by Afghan army units, will pick up the slack of American combat units preparing to leave the country by 2014.
That postwar involvement of American forces in Afghanistan would focus on providing intelligence and support for Afghan National Security Forces via U.S special-operations units.
Roughly 33,000 U.S. service members funneled into the so-called Taliban heartland of southern Afghanistan under the Obama administration's 2009 surge have since been pulled out of the country.
Gen. John Allen, the top U.S. commander in Afghanistan, is expected to submit his strategy to pull out the remaining 68,000 American troops from Afghanistan within the next year-and-a half.