WASHINGTON -- Two major investigations examining the performance of U.S. intelligence agencies have discovered an old Washington institution: the stonewall.

One probe is looking into what the U.S. government knew about the terrorist threat before the Sept. 11 attacks. The other investigation asks what the U.S. government knew about Iraq before the invasion.

Both inquiries could be billed as the search for truth. If only it were that simple.

The National Commission on Terrorist Attacks co-chaired by former New Jersey Gov. Thomas Kean, a Republican, and former Rep. Lee Hamilton, D-Ind., is facing a May 27 legal deadline to finish its work. Foot-dragging by the executive branch -- a time-honored stonewalling tactic -- is equivalent to running out the clock in a football game.

That shouldn't be a great surprise in view of President Bush's adamant opposition to the creation of the commission in the first place. He caved in only after it became clear that Congress was going to create the tribunal anyway.

A group of Democratic senators wrote to Bush earlier this week decrying the administration's withholding of classified documents "after months of frustratingly slow negotiations ... which may make it impossible for the commission to finish its work before the statutory deadline."

In a new get-tough posture with the Defense Department, the commission voted Friday to subpoena records of the North American Aerospace Defense Command (NORAD) for Sept. 11, 2001, the day of the attacks.

The panel said it was "especially dismayed" over "some serious delays" in obtaining needed documents and the fact that the Pentagon had given assurances that all requested records had been turned over when the commission later discovered that claim was false.

The Senate Intelligence Committee trying to obtain the secret memos and CIA documents that Bush said were the basis for his decision to invade Iraq also is running into the administration's stonewall.

The committee is asking for copies of the Bush's daily intelligence briefings in the days leading up to the war.

A typical White House stonewall consists of public pledges of cordial cooperation with investigators, followed by private resistance, delay, excuses, partial compliance or self-righteous assertion of constitutional prerogatives.

White House press secretary Scott McClellan, while reminding reporters that Congress does not have jurisdiction over the presidency, still insists "we're willing to be helpful. We're working very cooperatively with them (the committee)."

If that's true, then why doesn't the White House hand over the documents being sought by the Senate committee?

Partisan political warfare shows signs of boiling over in the Senate committee.

On Tuesday, Fox News commentator Sean Hannity disclosed a Democratic memo that suggested Democrats were devising a political strategy to attack the administration's handling of intelligence before it invaded Iraq.

The memo recommended that Democrats should play up "the misleading, if not flagrantly dishonest methods and motives of senior administration officials who made the case for unilateral preemptive war."

The leaked memo was reportedly traced back to the embarrassed office of Sen. Jay Rockefeller, D-W.Va., the vice chairman of the committee, who had not approved it.

Sen. Pat Roberts, R-Kan., chairman of the committee, said the memo shows that the Democrats intend to politicize the investigation.

House Speaker Dennis Hastert, R-Ill., accused the Democrats of wanting "to play politics with our intelligence agencies, as those agencies fight the war on terror."

Both panels are running into the familiar stonewall rationale of "national security."

Roberts has said it probably will be next year before the committee holds public hearings and issues its report.

Everyone who sat in the White House press room for the last two years knows that the Bush administration was determined to invade Iraq, no matter what the CIA was able to dig up.

The prelude to 9/11 is more mystifying, given the murky nature of global terrorism. The Kean-Hamilton commission doesn't need additional obstacles in the form of an uncooperative White House.

(Helen Thomas can be reached at the e-mail address hthomas@hearstdc.com).