The sentence is one of several that describe U.S. vulnerabilities in the document, released Friday, titled "The National Defense Strategy of the United States of America."

"Our strength as a nation state will continue to be challenged by those who employ a strategy of the weak focusing on international fora, judicial processes and terrorism," it says. It does not go into detail.

Asked about the statement, Douglas Feith, the No. 3 official at the Pentagon, said during a news conference, "There are various actors around the world that are looking to either attack or constrain the United States, and they are going to find creative ways of doing that, that are not the obvious conventional military attacks."

He went on, "We need to think broadly about diplomatic lines of attack, legal lines of attack, technological lines of attack, all kinds of asymmetric warfare that various actors can use to try to constrain, shape our behavior."

Asked to clarify what a "legal line of attack" meant, he acknowledged it could include the International Criminal Court, a body vehemently opposed by the Bush administration, that began operations in The Hague in 2003. The U.S. government has sought agreements with other countries that they would not transfer U.S. soldiers for prosecution by the court.

Feith, the outgoing undersecretary of defense for policy, denied the reference would include a detainee at Guantanamo Bay, Cuba, suing the U.S. government for his freedom. He said it was meant to note "the arguments that some people make to try to, in effect, criminalize foreign policy and bring prosecutions where there is no proper basis for jurisdiction under international law as a way of trying to pressure American officials."

Other vulnerabilities include inconsistent or less-capable allies and resentment of U.S. influence in world affairs, the document says. In a town-hall meeting at the Pentagon earlier Friday, Defense Secretary Donald H. Rumsfeld complained about one of those allies, calling Spain's abrupt withdrawal of 1,300 troops from Iraq last year "not impressive."

Overall, the document confirms Rumsfeld's policies in the broadest terms: It is impossible to know when and where the next threat to U.S. security will come - what Pentagon planners call "strategic uncertainty" - so the U.S. military needs to be able and flexible enough to deploy anywhere in the world in short order.

The document also accents needs for allies to provide bases for U.S. forces and to search their own countries for extremists who intend to attack the United States.

Still, the document leaves open the possibility the United States would act preemptively and alone. "We will act with others when we can," it says.

The document will be used to help shape the Quadrennial Defense Review, a far-reaching project now under way that will try to outline what military capabilities the United States needs to meet the goals of this strategy. Rumsfeld will present the review to Congress early next year.

Feith acknowledged that the United Kingdom and other allies will now be allowed to take part in secret meetings as the review is developed.