ASHINGTON, Sept. 16 ・When President Bush and his top aides talk about military action to end Afghanistan's support for terrorism, they are focusing on attacks to punish the Taliban and undermine their control over the country, not a full-scale American occupation.

No war plan appears to have been agreed on, and officially the Bush administration insists that no options have been excluded.

The administration, however, is preparing a powerful military strike if the Taliban, as expected, refuse to hand over the terrorist Osama bin Laden and shut down his terrorist network.

The blow would be intended not only to destroy terrorist bases in Afghanistan but also to demonstrate to other nations that there is a heavy cost to be paid for those who shelter enemies of the United States.

A principal option is to intervene militarily in Afghanistan's civil war on the side of the Taliban's foes: the beleaguered rebel alliance that claims just a sliver of Afghanistan's territory. It was just weakened further with the assassination of its leader, Ahmed Shah Massoud, who died Saturday, after a bomb attack committed just two days before the raids in New York and Washington.

At the same time, the United States would apply additional pressure, for example, by persuading Pakistan to close off financial channels to the bin Laden organization and the flow of fuel to Afghanistan.

Such steps might fall short of a knockout blow to the Taliban. Complicating the administration's planning, the element of surprise has been lost. The Taliban and Mr. bin Laden's men are expecting a bombing attack and have been evacuating their camps and bases, according to American intelligence.

But there is a recognition that to go further by carrying out a Soviet-style occupation with thousands of troops would place the United States at odds with much of the Islamic world and is fraught with danger.

The administration seems to be grappling for a plan involving air power, and potentially ground troops, that is more forceful than the cruise missile strike that the Clinton administration launched in 1998 against Mr. bin Laden in Afghanistan ・with little effect ・but that is less than the huge air and ground offensive that the United States launched in the Persian Gulf war.

Administration officials indicated that military action against Afghanistan need not be an urgent matter without the element of surprise. Indeed, the Pentagon will need time to position its forces if it decides to carry out a major attack in a distant region like Afghanistan, far from American bases.

But administration officials also know that politically it will be easier to take action while world outrage over the terrorist attacks against the World Trade Center and the Pentagon is still fresh.

The military action being planned for Afghanistan is part of a broader diplomatic as well as military policy of holding nations accountable that provide aid and comfort to terrorists.

The administration's goal is clear: it wants to rip apart the terrorists' networks. But since the terrorists are hard to find, Washington is focusing not just on them but on the governments that back them. Certainly capturing a terrorist or enemy leader is one of the most difficult of military tasks.

The American military tried in vain to capture the Somali warlord Muhammad Farah Aidid. And it failed to break Saddam Hussein's hold on power despite numerous raids including some devised to kill the Iraqi leader.

The first Bush administration was successful in apprehending Manuel Noriega, the Panama strongman. But Washington had many advantages, including American military bases and airfields in Panama.

But Mr. bin Laden has been elusive and has based himself in a rugged region, remote from American bases and forces. Vice President Dick Cheney said today that the United States was not even sure that Mr. bin Laden is still in Afghanistan. Faced with a difficult task of tracking him down, the Bush administration has responded by enlarging the problem. The theory is that while the terrorist may be hard to find, a government that shelters him is not.

"The terrorist organizations themselves and the terrorists don't have targets of high value," Defense Secretary Donald H. Rumsfeld said today on the Fox News Channel. "They don't have armies and navies and air forces that one can go battle against. They don't have capital cities with high-value assets that they're reluctant to lose."

He added: "Some of the countries that are harboring terrorist networks do, in fact, have high-value targets. They do have capitals. They do have armies." Deputy Secretary of State Paul D. Wolfowitz spoke last week of "ending states who sponsor terrorism." Officials say now that he misspoke, that he meant to say that the goal is ending state support.

In some cases, like Afghanistan, that may be a semantic issue since the goal would be to dislodge the Taliban rulers if they refused to cooperate with Washington's counterterrorism campaign.

In other cases, political, economic and limited military pressure may be applied. The Bush administration has certainly not committed itself to invading all the nations on the State Department's list of those found to help terrorists ・Iran, Iraq, Syria, Sudan, Libya, Cuba and North Korea.

And it may be prepared to show some tactical flexibility. Some officials say that they do not exclude cooperating with Iran, a supporter of the anti-Taliban insurgents, in their quest to take the fight to the Taliban. That would be an application of the old dictum "The enemy of my enemy is my friend."

In a country as poor as Afghanistan, there may be precious few of the high-value targets that Mr. Rumsfeld referred to. But there are still bases, police posts and forces that the United States could strike. Certainly the main focus is on targets in Afghanistan.

Mr. Cheney said there was no indication that Iraq was linked to last week's terrorist attacks in New York and Washington. "Saddam Hussein's bottled up at this point," he said.

Recognizing the difficulty of its military task, the Bush administration has also been avoiding expectations that one or two raids will put an end to the worldwide terrorist threat. It is talking about a military campaign that would last years, not months.

"What we have to do is take down those networks of terrorist organizations," Mr. Cheney said today. "I think this is going to be a struggle that the United States is going to be involved in for the foreseeable future."