“The Army has been in a state of continuous war for nearly 12 years, the longest in our nation’s history,” Odierno said, “but today, in my opinion, the greatest threat to our national security is the fiscal uncertainty resulting from the lack of predictability in the budget cycle.”
The United States Constitution, Article I, Section 8, Clause 12 establishes that Congress alone has the power "[t]o raise and support Armies, but no Appropriation of Money to that Use shall be for a longer Term than two Years." Clause 13 speaks to the Navy. The "lack of predictability in the budget cycle" is purely about Congress' determination of budgets.
Specifically, it is about the failure of Congress to determine a budget. Congress has not passed a budget in more than three years. The sole and only reason that there is uncertainty of the type General Odierno describes is that Congress has not done its duty.
That may be a first in American history. The Chief of Staff of the US Army publicly stated that the effects of Congress' actions are the largest national security threat to our country.
He put it very politely, even obliquely, as the UCMJ severely restricts servicemembers' criticisms of elected officials. Nevertheless, there is simply no other way to read his remarks.