(CBS/AP) A former CIA director and a former deputy national security adviser on Tuesday advocated major changes to the U.S. intelligence establishment in testimony before the independent commission studying the terror attacks of Sept. 11, 2001.

John M. Deutch, CIA director from 1995-1996, and James B. Steinberg, deputy national security adviser in the Clinton administration, endorsed two structural reforms: appointing a director of national intelligence separate from the CIA, and creating a domestic security service modeled after Britain's MI5.

"Although some progress has been made," Deutch said in written remarks to the commission, "I doubt that it will be possible to obtain the intelligence capability this country and its citizens deserve without a dramatic realignment that creates an executive authority that places national security first."

In an interview on the eve of his testimony, Steinberg said U.S. counterterror efforts remain hampered by decades-old walls separating by law the work of the FBI and CIA. The FBI operates domestically and traditionally focuses on catching law-breakers; the CIA works abroad and focuses on learning secrets.

"The beauty of the MI5 model is it breaks down both those walls," said Steinberg, director of foreign policy studies at the Brookings Institution.

The National Commission on Terrorist Attacks Upon the United States, which is reviewing intelligence failures as part of its probe of Sept. 11, was also hearing Tuesday from a second former national intelligence director who cautions against dramatic realignment.

"No one would question that management can always be improved, but major organizational change is not the salvation," James Schlesinger, director of central intelligence in 1973, said in his prepared testimony.

He added, "I would submit that the real challenge lies in recruiting, fostering, and motivating people with insight — and, when necessary, bring about long-term change in the ethos of intelligence organizations."

The 10-member, bipartisan commission is considering changes in U.S. intelligence that would go well beyond actions by the Bush administration. The panel has until May 27 to submit a report dealing with law enforcement, diplomacy, immigration, commercial aviation and the flow of assets to terror organizations.

Talk of changing the U.S. intelligence agencies stems from concerns that they do not work closely together. A joint House-Senate inquiry after the Sept. 11 attacks concluded that serious failings by U.S. intelligence leaders left the country vulnerable.

Commission chairman Thomas H. Kean said the panel has several ideas to make U.S. intelligence more effective, "including the question of whether the United States should establish a Director of National Intelligence."

Sen. Dianne Feinstein, D-Calif., has proposed legislation to split the duties of the current director of central intelligence into two jobs: a CIA director and a national intelligence director.

The national intelligence director, appointed by the president and confirmed by the Senate to a 10-year term, would oversee all intelligence agencies, setting priorities for collecting information and monitoring cooperation. The CIA director's duties would be limited to running that one agency.

The idea of a new U.S. domestic security agency gained momentum last year when Homeland Security Director Tom Ridge visited MI5 headquarters in Britain. But Ridge said he doubted the Bush administration would create a similar agency because MI5's powers would be unacceptable under the U.S. Constitution.

FBI Director Robert Mueller also opposes the idea of an American MI5.

MI5 describes itself as Britain's defensive security intelligence agency. It is the domestic partner to MI6, the foreign intelligence agency.

MI5 cannot detain or arrest its targets, but seeks to "to gain the advantage over (them) by covertly obtaining information about them" for countering their activities.

Reflecting the difference in approaches across the Atlantic, MI5 is resisting a move by Prime Minister Tony Blair's government to allow wiretap evidence to be used in criminal trials, according to the Guardian newspaper. The spy agency is concerned such a move would allow suspects to learn too much about MI5 tactics.

In contrast, the Justice Department recently won the right to use a secret intelligence court to issue wiretap warrants that might obtain information used in criminal proceedings.

The Bush administration has worked to improve intelligence gathering and sharing since the Sept. 11 attacks. It created a Terrorist Threat Integration Center to bring together information gathered by the CIA, FBI and other agencies. The center reports to the CIA director but is not part of the agency.

Also, President Bush recently said the FBI, under new powers granted by the USA Patriot Act, "is now dedicated to preventing future attacks" instead of just investigating past crimes.

Besides the FBI and CIA, the U.S. intelligence apparatus includes the National Security Agency, the Defense Intelligence Agency, the National Reconnaissance Office, and the National Imagery and Mapping Agency.

In addition, the Air Force, Army, Navy and Marine Cops all have intelligence departments, as do certain civilian agencies, like the Departments of Energy, Homeland Security and State.

While there is often consensus, some of these entities had disagreements over the intelligence on Iraqi weapons of mass destruction. Air Force Intelligence, for example, doubted that Iraqi drones were primarily intended for dispensing chemical weapons.

The State and Energy departments dissented on some of the nuclear weapons allegations, and the State Department questioned whether two trailers found in northern Iraq were really mobile biological weapons factories, as the CIA suspected.