The landing of hundreds of US marines near the southern Afghan city of Kandahar gives the war against terrorism increased tangibility. American lives will now clearly be on the line as these soldiers fan out to track down Osama bin Laden or join attacks on the Taliban's remaining strongholds.
The marines' deployment signals that Washington is indeed willing to heighten the risk of casualities, despite past concerns that a post-Vietnam America would not tolerate large losses in a conflict.
That grim commitment is necessary to finish the job in Afghanistan and to demonstrate to allies and onlookers around the world that the strong words emanating from Washington since Sept. 11 would be backed by action.
This deployment carries even more risks. Afghans must be convinced that this foreign military presence is only short-term and tightly focused in its tasks. There can be no whiff of "occupation." Afghanistan may have foreign military contingents on the ground for the indefinite future, but they should be UN peacekeepers, helping restore calm as Afghans themselves rebuild.
Sending in the marines also hints at a strong US willingness to go after other governments that help global terrorists. The possibility, for instance, of invading Iraq is only speculative for now, mainly because such an action could have dangerous richochet effects among Arab nations. But the point has been made.
The marines embody US determination to defend the homeland anywhere. This land campaign, following a successful air bombardment, shows the US will defend itself at any cost.