The strategy turns the page on Bush-era dreams of remaking the global order with American might and recognizes the increasing global engagement of Russia and the emergence of rising powers like China and India.
"To succeed, we must face the world as it is," the document states.
In putting the first public face to the document, US Secretary of State Hillary Clinton confidently asserted American power but said it would be used more wisely and less directly than before.
"We are no less powerful," the chief US diplomat told foreign policy experts at the Brookings Institution think tank, adding that US military and economic power remained "unmatched."
But the United States is "shifting from mostly direct exercise and application of power to a more sophisticated and difficult mix of indirect power and influence," Clinton said.
She cited powers ranging from its democratic values to technological innovation.
And she said the United States would harness its "comparative advantage" to "convene and connect broader coalitions of actors."
Indeed, the new doctrine illustrates an evolution of Obama's pro-engagement policies after 16 months in power, a period that brought the idealism of his election campaign into conflict with the harsh realities of geopolitics.
Clinton acknowledged that traditional "slow, patient diplomacy" was more difficult today than in the past.
But she said the United States -- which she lists among a few nations having "the luxury" of viewing their national interests broadly -- works to persuade other countries to focus less narrowly.
She cited Israel as an example, about how it needed to make peace with the Palestinians or end up running the risk of ruling over a non-Jewish majority in the future.
Echoing the document's points on what she calls "smart power," Clinton committed to using the sweeping range of foreign policy tools, including diplomacy, economic renewal, development aid, military might and education.
The doctrine calls for tough engagement "without illusion" with US foes like Iran and North Korea, but warns they face deepening isolation if they continue to spurn US advances and fail to throw open their nuclear programs.
The 52-page strategy also preserves the US right to launch unilateral military action, but does so in more restrictive terms than those used by the former Bush administration.
It also seeks to widen the scope of US foreign policy, which became dominated by a doctrinaire "war on terror" following the September 11 attacks in 2001, and led to the war in Iraq, after the invasion of Afghanistan.
"We will always seek to delegitimize the use of terrorism and to isolate those who carry it out," said the document, the product of intense internal deliberations during the 16 months of the Obama administration.
"Yet this is not a global war against a tactic -- terrorism -- or a religion -- Islam.
"We are at war with a specific network, Al-Qaeda, and its terrorist affiliates who support efforts to attack the United States, our allies, and partners."
In his final national security strategy in 2006, Bush targeted terrorism as a concept more specifically, declaring boldly "the war on terror is not over."
In a broader framework, the document sets out a platform for robust engagement, the maintenance of the US military edge and wide social diplomacy and development assistance.
"Our long-term security will not come from our ability to instill fear in other peoples but through our capacity to speak to their hopes," Obama said in a message introducing the new strategy.
The strategy lists a set of comprehensive threats facing the United States, beginning with the most grave -- the threat of weapons of mass destruction, especially nuclear weapons.
For the first time, the new strategy makes combating homegrown extremists, "radicalized" on US soil, a key plank of security policy.
"Our best defenses against this threat are well-informed and equipped families, local communities, and institutions," the document said.
"The federal government will invest in intelligence to understand this threat and expand community engagement and development programs to empower local communities."
National Security Adviser General James Jones said the new strategy marks two firsts, by highlighting the importance of cybersecurity and by elevating the role of the G-20 in international economic cooperation.
--------------------------------------------------------------------------