We are approaching seven years since Sept. 11, 2001, and the subsequent invasion of Afghanistan to destroy the orchestrators of the attacks: Osama bin Laden and his al Qaeda network. Yet intelligence officials report that the United States is more vulnerable today to foreign threats than at any time since the planes destroyed the World Trade Center and parts of the Pentagon.

A long “War on Terror” has ensued since Sept.  11, but the primary front has been declared in the wrong place.

The fight should be wherever Osama bin Laden and his top lieutenants are hiding — and they are not holed up in downtown Baghdad.

For five years, we have been ensnared in a sectarian civil war in Iraq that has cost more than 4,000 American lives and more than a half-trillion dollars.

An old saying goes that a fish rots from the head, and by losing our focus on defeating al Qaeda’s global network, it appears we have spent all our time focusing on the tail.

In the Defense authorization bill signed into law earlier this year, Congress called for a policy shift to focus the U.S. counterterror effort on capturing or killing bin Laden, his second-in-command Ayman al-Zawahiri, and dismantling their network of al Qaeda terrorists. The next administration should follow Congress’s direction and immediately reprioritize targeting al Qaeda’s head, hiding somewhere along the Afghanistan-Pakistan border.

Our own National Intelligence Estimates clearly state that al Qaeda is the most serious threat to U.S. soil. While we continue directing most of our resources to Iraq, these reports indicate the insidious terror network has been allowed to grow stronger, smarter and more agile. Americans must not ignore the bin Laden and al-Zawahiri video and audio recordings that serve to mock our freedom and call to action impressionable young men and women in every corner of the Middle East.

But in shifting our focus from fumbling through a civil war to facing our nation’s principal enemies, we must not take our eye off threats lurking on the horizon. The U.S. military is already making positive strides in combating the new threats of cyber attack on U.S. technology infrastructure. At the forefront of this effort is Barksdale Air Force Base in Bossier City, La., which is developing a Cyber Command to lead efforts to combat this emerging tactic. Their work could not be more important. A significant cyber attack could cripple our government and send shock waves that cause our economy to tumble.

Last year in Estonia, a NATO ally, government websites were deluged with a flood of coordinated traffic, a strategy known as a “denial of service attack.” This was followed up by an assault on the Parliament's e-mail service and on the country's banks. In all, Estonia experienced a three-week, piercing cyber attack that infiltrated every aspect of its society, which is one of the most Web-dependent in the world. The Estonian experience provides a real-world example of the devastating potential a large-scale cyber attack could have on in the United States. For al Qaeda and other terror groups and emerging powers, a single computer and Internet connection can be a powerful first-strike weapon. Given American connectivity and reliance on the Internet in our homes, in commerce and at many levels of vital infrastructure, American vulnerability is obvious.

Some rogue governments are actually training armies of cyber warriors. In Burma, the military junta has established an elaborate cyber warfare section within its secret police. North Korea has a cyber warfare school that turns out 100 “infowarriors” every year. This program is said to be supplemented by a five-year training program for North Korean troops within China.

As a result, attempted cyber attacks on the U.S. government are increasing. Last week, Reps. Frank Wolf (R-Va.) and Chris Smith (R-N.J.) said Chinese hackers have accessed computers in multiple offices in the House. The Pentagon’s network of cyber security is penetrated 60 to 80 times a day by hackers.

The next administration, with Congress’s support, has the heavy task of homing in on the menace that attacked us on Sept. 11 and preparing us against future threats. Facing these will require increasing investment in the technology and infrastructure to ramp up our ability to face amorphous threats on the home front. Louisiana is proud to stand on this front line.

Landrieu is a member of the Senate Homeland Security and Governmental Affairs Committee.