Top military brass told a Senate panel on Tuesday that political gridlock in Washington is affecting the readiness of America's military.
Under the so-called sequester that goes into effect March 1, the Pentagon faces $46 billion in budget cuts, on top of nearly $500 billion in cuts already in place.
Officials say there's also no budget in place for the current fiscal year.
"The cloud of uncertainty hanging over our nation's defense affairs is already having lasting and irreversible effects," Deputy Secretary of Defense Ashton Carter said.
"Today, the global environment is the most uncertain I've seen in my 36 years of service. It is unpredictable and dynamic. We simply don't know when we will have to deploy soldiers to fight again," Amy Chief of Staff Gen. Ray Odierno said.
"The signal we are sending, frankly to the Iranians, is 'Don't worry, this aircraft carrier is not coming," Sen. John McCain, R-Ariz., said.
Defense cuts can be avoided if Congress and the president agree on a plan to trim the deficit by more than $1 trillion over the next 10 years.