On Guard

Just 24 hours ago, it was a given that governments in the U.S. and Europe would issue travel advisories, based on a heightened terrorist threat in France, Germany and other countries.

Still, the warnings actually issued are a bit surprising, suggesting that the threat is very serious, and that some sort of terror attack may be inevitable.

As evidence of that, consider the highly unusual travel advisory issued today by the State Department, for Americans planning to visit to Europe. As ABC News reports:

"The State Department alerts U.S. citizens to the potential for terrorist attacks in Europe," says the advisory. "Current information suggests that al Qaeda and affiliated organizations continue to plan terrorist attacks."

While the advisory does not name potential targets, it says "U.S. citizens are reminded of the potential for terrorists to attack public transportation systems and other tourist infrastructure." It recommends that U.S. citizens "take every precaution to be aware of their surroundings" and register their travel plans on the State Department's travel registration web site.

The warning was issued amid growing concerns that multiple terrorist teams have arrived in Europe and are planning to carry out "Mumbai-style" attacks in Germany, France or other locations. Two years ago, Islamic terrorists stormed a luxury hotel in Mumbai, India, killing more than 170 tourists and security personnel.

Sources tell ABC that Osama bin Laden has approved plans for similar attacks against "soft" targets in Europe, including airports and tourist hotels. ABC also reports that terrorist operatives are in position near potential targets, have checked in with their controllers in Pakistan and received the go-ahead to strike. That suggests that recently-increased security measures in Europe have failed to apprehend some terror teams, increasing the likelihood of attacks in the coming days.

Al Qaida was apparently able to deploy operatives to Europe despite increased strikes from U.S. drones in Pakistan. American Predator and Reaper UAVs have stepped up attacks against suspected terror training camps and support sites in Pakistan's tribal regions in recent weeks. Intelligence and security officials say the raids were aimed at blunting potential terror strikes against European targets, by eliminating operatives and other key personnel at the Pakistani facilities.

Following the U.S. move, Britain's Foreign Office has already upgraded its terrorist advisory for Europe, saying there is a "high threat" of attacks in Germany, France and other countries. The British warning is only one step below the highest advisory, which recommends no travel at all.

Officials in London say they concur with their U.S. counterparts, who are warning of possible strikes against both public and private interests, including transportation systems.

Meanwhile, there are continuing concerns that other terrorist elements are taking aim at the American homeland. Sources told ABC that "recent law enforcement operations in the U.S. have helped 'flush out' additional chatter," adding to concerns that the homeland may also be a target.

The Transportation Security Administration (TSA) conducted a pair of high-profile truck search operations along I-20 near Atlanta last week. Officials first described the effort as a "training exercise," but other law enforcement agencies participating in the effort confirmed it was a "counter-terror" operation. Hundreds of trucks were searched during the two-day operation, which snarled traffic along I-20 for hours.