U.S. Army General Mark Milley
© Jonathan Ernst / Reuters U.S. Army General Mark Milley
Despite his confidence in US troops to fight insurgencies, Army Chief of Staff Gen. Mark Milley voiced "grave concerns" at a congressional budget hearing about the military's capability if it found itself in a war with Russia, China, Iran, or North Korea.

Gen. Milley's testimony on Wednesday to the House Armed Services Committee assured legislators of the military's "good, current capability and capacity" to combat Islamic State and other terrorist insurgencies in countries like Afghanistan. But after nearly 15 years of such missions along with more recent troop cuts, the top general said readiness for a "great power war" had been depleted.

The great powers were named as China, Iran, North Korea and Russia, and Gen. Milley stressed to lawmakers that the American people would expect the US to be able to hand any two of them at a time, but that that wasn't realistic under current circumstances.

"I think the cost, both in terms of time, casualties in troops, and the ability to accomplish military objectives would be very significant, and we've all given our risk assessments associated with that in a classified session," Gen. Milley said.

Filed by Rep. Chris Gibson (R-New York) and Rep. Mike Turner (R-Ohio), the Army's budget request of $148 billion for the fiscal year 2017, which begins October 1, 2016, is an increase of nearly a billion dollars from fiscal year 2016. It would, however, delineate Army troop levels down to 460,000 active duty soldiers from the 475,000 on active duty today, and the Marines would be cut slightly, from 184,000 to 182,000.

"In terms about the European Reassurance Initiative, dealing with the Islamic State, concerns about North Korea, some challenges potentially with China," Rep. Gibson said, according to The Hill. "This is a very important bill that we need to muster the political will to pass."