WASHINGTON -- Congress stripped a provision Tuesday from a defense bill that aimed to shield Americans from the possibility of being imprisoned indefinitely without trial by the military. The provision was replaced with a passage that appears to give citizens little protection from indefinite detention.

The amendment to the National Defense Authorization Act of 2013 was added by Sen. Dianne Feinstein (D-Calif.), but there was no similar language in the version of the bill that passed the House, and it was dumped from the final bill released Tuesday after a conference committee from both chambers worked out a unified measure.

It declared that "An authorization to use military force, a declaration of war, or any similar authority shall not authorize the detention without charge or trial of a citizen or lawful permanent resident of the United States apprehended in the United States, unless an Act of Congress expressly authorizes such detention."

The provision sparked a heated debate in the Senate, but ultimately passed by a wide majority with both supporters and opponents of U.S. terrorist detention practices voting for it, citing differing interpretations. Feinstein offered the amendment to clarify a part of the 2012 NDAA that for the first time codified the ability of the military and White House to detain terrorism suspects.

Spokespeople for Senate committee leaders did not immediately answer why the amendment was stripped, but pointed to the language that replaced it:

Nothing in the Authorization for Use of Military Force (Public Law 107–40; 50 U.S.C. 1541) or the National Defense Authorization Act for Fiscal Year 2012 (Public Law 112–81) shall be construed to deny the availability of the writ of habeas corpus or to deny any Constitutional rights in a court ordained or established by or under Article III of the Constitution to any person inside the United States who would be entitled to the availability of such writ or to such rights in the absence of such laws.

The new provision appears to do little, because the Supreme Court has already declared that the writ of habeas corpus -- requiring that someone be presented to a judge -- applies to all people. The more difficult part of whether people deserve a trial remains unsettled, and the new provision does not appear to resolve it.

"This language doesn't do anything of substance," said Raha Wala, a lawyer in the law and national security program of Human Rights First. "It doesn't ban indefinite detention within the United States or change anything about existing law."

Feinstein said she was not pleased that her attempt to at least shield citizens and legal residents was stripped.

“I was saddened and disappointed that we could not take a step forward to ensure at the very least American citizens and legal residents could not be held in detention without charge or trial," Feinstein said. "To me that was a no-brainer.”

Nevertheless, many activists who oppose indefinite detention were not all that enamored with her amendment because some felt it asserted that Congress had the right to make laws requiring detention of citizens. Others believed it failed the test of constitutionality because the Constitution specifies its protections extend to all people, not just citizens. It also did not address terror suspects captured overseas.

The White House had threatened to veto both the House and Senate versions over numerous other provisions included in the legislation. Among them were restrictions on the executive's ability to transfer prisoners from the prison for terrorist suspects at Guantanamo Bay, Cuba.

The White House did not immediately answer questions about whether the threats stood.

UPDATE: 5:25 p.m. -- Conservative Kentucky Sen. Rand Paul (R), slammed the change, singling out Sen. John McCain (R-Ariz.) in the process.

“The decision by the NDAA conference committee, led by Sen. John McCain (R-Ariz.) to strip the National Defense Authorization Act of the amendment that protects American citizens against indefinite detention now renders the entire NDAA unconstitutional,” Sen. Paul said.

“I voted against NDAA in 2011 because it did not contain the proper constitutional protections. When my Senate colleagues voted to include those protections in the 2012 NDAA through the Feinstein-Lee Amendment last month, I supported this act,” Sen. Paul continued. “But removing those protections now takes us back to square one and does as much violence to the Constitution as last year’s NDAA. When the government can arrest suspects without a warrant, hold them without trial, deny them access to counsel or admission of bail, we have shorn the Bill of Rights of its sanctity.

“Saying that new language somehow ensures the right to habeas corpus – the right to be presented before a judge – is both questionable and not enough. Citizens must not only be formally charged but also receive jury trials and the other protections our Constitution guarantees. Habeas corpus is simply the beginning of due process. It is by no means the whole.

“Our Bill of Rights is not something that can be cherry-picked at legislators’ convenience. When I entered the United States Senate, I took an oath to uphold and defend the Constitution. It is for this reason that I will strongly oppose passage of the McCain conference report that strips the guarantee to a trial by jury.”

Michael McAuliff covers Congress and politics for The Huffington Post. Talk to him on Facebook.