As a US military commander heads into Liberia to help stabilize its war-torn capital, it won't be the first time American forces have carried out new operations in Africa lately.
On the continent's east coast, a US antiterror base in Djibouti recently expanded to include some 2,000 troops. In northwest desert nations such as Mali, US advisers have given all-terrain vehicles and special-operations training to military and police units.
It all seems an echo of the cold war, with the US establishing a small but growing presence in some of the globe's remotest regions. During the era of US-Soviet tensions, it was places like Vietnam, Nicaragua, and Angola that Washington considered proxy battlefields. Now it's Afghanistan, Kenya, the Philippines, and other nations that are flash points in the war on terror - places where the US is risking more involvement in often complex environs to prevent terror's spread.
Africa is of particular concern because it's home to the world's biggest group of failed states, which can be terrorist incubators. It's also the source of nearly one-fifth of US crude-oil imports - a number that's expected to grow.
Not that Africa's 54 nations are suddenly a major focus of US foreign policy. But experts say the war on terror gives the US new reasons to at least monitor destabilizing conflicts like Liberia's 14-year civil war.
"When the cold war ended, America's strategic interest in Africa ended. But on Sept. 11, that changed," says Jack Spencer, a senior defense analyst at the conservative Heritage Foundation in Washington.
Whether the US has a strategic interest in Liberia is up for debate. And President Bush's reluctance to let more than a handful of US troops go ashore may reflect deep American ambivalence.
But now that ex-President Charles Taylor has left the country, at least a few more US troops are expected to put boots on the ground. Tuesday, the US regional commander left a warship floating off the coast and flew by helicopter into the capital, Monrovia, to assist with securing the port, in part so aid groups can get food to residents.
To some, Liberia represents a prime opportunity for the Bush administration to showcase to the world, the UN, and even Muslim nations that America's commitment to Africa - and to bolstering failing states - is strong.
"The US and the West need a demonstration state - a state that has turned around from being in abysmal shape," says Robert Rotberg, an Africa scholar at Harvard University. Given US struggles in Iraq and Afghanistan, Liberia would be highly useful.
Furthermore, there are reports of possible money laundering related to Al Qaeda in Liberia.
Tuesday, new fighting between government forces and the two rebel groups resumed, the day after Mr. Taylor left for exile in Nigeria.
Despite the continued clashes, many argue there's no compelling case for serious US involvement there, especially given the strategic necessities elsewhere.
A primary area of focus in Africa is a cluster of nations near the Horn of Africa, including Kenya, Somalia, Ethiopia, and Eritrea. In Kenya, despite official cooperation in the war on terror, Islamic groups are blossoming. Anti-American sentiment can run strong, especially in the port city of Mombasa. A bomb attack there in November killed Israeli visitors, and a heat-seeking missile narrowly missed an Israeli charter jet during takeoff.
In Djibouti, meanwhile, US forces have set up a regional anti-terror hub that focuses on Africa and nearby Arab nations, including Yemen. US aid to Djibouti has reportedly jumped from about $3 million per year before Sept. 11 to some $10 million today. It's expected to increase further.
US military officials based in Djibouti have reportedly disclosed the capture of numerous Al Qaeda-connected operators from across the region.
Another area of US focus is a group of countries in Liberia's neighborhood, including Mali, Niger, Mauritania, and Nigeria. In June, a possible truck-bomb attack on the US Embassy in Mali was reportedly scuttled by American and local authorities. US officials have been working to persuade governments in the region - especially Nigeria - to crack down on criminal gangs, which could help terrorists with such things as money laundering.
Given the region's volatility, having US warships off the continent's west coast - as they have been for several weeks in connection with Liberia - could become a more-regular event. NATO Supreme Commander James Jones in May identified the growing risks in the region: "a certain number of countries that can be destabilized in the near future, large ungoverned areas across Africa that are clearly the new routes for narco-trafficking, terrorist training and hotbeds of instability."
In response, he foresaw a bigger US presence, predicting that, in the future, American warships may "spend half their time going down the west coast of Africa."