Military experts say the US and Britain are shaping up for a brief "cosmetic" strike against Afghanistan followed by a longer campaign of attrition.
As the Taliban show no sign of giving up Osama bin Laden, options for taking him by force are being drawn up by strategists on both sides of the Atlantic. Their main difficulty may be knowing precisely where he is hiding.
Although the Saudi-born renegade - "wanted dead or alive" by US President George W Bush - has a personal following of up to 2,000 Mujahideen militiamen, he is unlikely to have sought their protection.
Instead, he is "probably roaming the countryside with about six or seven people in a couple of Toyota pick-up trucks" to avoid drawing attention to himself, according to Major Charles Heyman, editor of Jane's World Armies.
"The Americans have probably lost him. Bin Laden has a great ability to vanish into the hills," he said.
With the operation to locate and seize the terror chief looking decidedly long-term, the US is likely to launch a largely cosmetic strike in the next few days for the benefit of public opinion, said Major Heyman.
"They're not going to hit much, but will launch some sort of air attack using cruise missiles or artillery."
The targets would be a Taliban regional headquarters or perhaps a car park full of armoured vehicles which is known to exist outside Kabul.
After that, a longer campaign would set in. Opinions on its nature vary, but one possibility is to mount a month-to-six-week offensive from the northern part of the country controlled by the Northern Alliance, a loose collection of groups opposed to the Taliban.
PA