Many of us awoke Thursday with a familiar lump in our throats and tug at our hearts. The morning news headlines that London had been rocked by a series of explosions targeting its public transportation network carried us back to the horrific events of Sept. 11, 2001, when terrorists claimed the lives of nearly 3,000 people in their attacks on the World Trade Center and the Pentagon and stole our nation’s innocence in the process.

Americans knew what the day would be like for our allies in London and Great Britain, and many of us – particularly those who lost friends and families in the 9/11 attacks – felt strangely discombobulated, our minds far away as we went about our work and daily routines. Though perhaps more accustomed to attacks than Americans as a result of the Nazi rockets in World War II that nearly flattened London and the decades-long Irish Republican Army bombing campaign, the savage attacks still had the power to numb our friends in Great Britain and strike fear in their hearts.

Reaction to the attacks, for which al-Qaeda in Europe claimed responsibility, was swift around the world. Terror alerts were raised throughout Europe, and increased scrutiny of public transportation systems was common throughout the United States, even in relatively quiet Des Moines, where the Metropolitan Transit Authority stepped up inspections of buses. Des Moines may seem an unlikely target for terrorists, but we learned four years ago to take nothing for granted.

The London bombings, which dampened the euphoria over the city’s selection to host the 2012 Olympics and cast a pall over the Group of Eight summit of world leaders in Gleneagles, Scotland, were a cruel reminder that despite a war that has cost the United States billions of dollars, terrorists’ talons still hold the world in an icy grip.

As our miltary’s attention was shifted from bringing the 9/11 terrorists to justice to a war in Iraq, we perhaps enjoyed a false sense of security. That, too, has been shattered. There will be time in the coming weeks to analyze whether British support of the U.S.-led invasion of Iraq contributed to the attacks in London, as some observers were speculating. For now, we join the rest of the world in issuing our condolences to our friends overseas and offering what little comfort that can be derived from the knowledge that we know how they feel.