By Emran Hossain

NEW YORK − On a brilliant summer’s day, a recent sunny visit to the National September 11 Memorial Museum in this metropolis also offered some stark reminders that the darkness that gathered after an attack that killed 3,000 Americans haunts the world still.

 Just days before my eye-opening visit to a dazzling Manhattan, Edward Snowden, an American citizen, worked with journalists in Britain and the United States to reveal details of a sweeping, global U.S. surveillance program that officials say aims to avert terrorist attacks.

 This highly secret and classified National Security Agency program, critics were quick to assert, undercuts the U.S. Constitution’s First- and Fourth-Amendment protections for Americans and creates global fears and apprehensions.

 As congressional leaders and administration officials, including President Obama himself, raced to the defense of the giant electronic data-collection efforts, the noisy claims and counterclaims – especially about the role of Snowden as whistleblower or traitor – stayed in my mind when I toured the World Trade Center site.

 A decade has passed since the chaotic, tragic day when two jet liners crashed into and toppled the landmark Twin Towers. Now, a large crowd flowed gently around me and my surroundings, many pausing to take in the scenic memorial pools.

 Cozy, happy tourists, most Americans, took countless photographs, mementoes of themselves with the rebuilt trade center structures in the background. Surely many of these snapshots were posted almost immediately on social networking sites.

 That, to me, was sad and richly ironic – those visual remembrances of those many slain were going on to a means of community communication that, if news reports are correct, are at the core of an international spy net.

 “I have heard of something like this” one of the visitors who looked more conscious than she turned out to be said of the NSA program when asked.

 Her response was unsurprising, based on my experiences, as Americans  display a  stratospheric reluctance to tackle, intellectually and otherwise, any matters that do not seem directly to involve their interests: A prevailing mindset might be characterized as, Hey, just enjoy or have fun.

 Still, as polls indicate, Americans continue to find terrorism “worrisome” and they haven’t yet risen up against waves of government intrusions into their rights as citizens in the name of countering “bad guy attacks.” They queue up, patiently by and large, and allow all manner of searches before they board planes; they’ve expressed concern but not outrage over their government’s listening in on telephone calls or intercepting, particularly overseas, arrays of electronic data, material collected with the cooperation – coerced or otherwise – of the nation’s tech elites at its top, now global Internet companies.

 A “bathtub falls and police officers kill more Americans than terrorism, yet we’ve been asked to sacrifice our most sacred rights for fear of falling victim to it,”  Snowden argued during an online Q-and-A session organized by The Guardian newspaper in Britain, a media organization that has broken many of the recent wave of stories about NSA programs.

Snowden, his defenders and critics of the U.S. government are demanding to know specifics about the NSA’s anti-terrorism surveillance and especially its results, arguing that information is critical so Americans may decide whether its trade-offs in possible losses of liberties are fair and just.

Even as U.S. leaders have made their case, however, the conversation itself, to me, has been chilling.

 In my home land of Bangladesh, international human rights groups and journalists have shone a grim light on the zealousness of government forces who act in the name of combatting corruption and terrorism. The special police force known as the Rapid Action Battalion, in particular, has drawn wide criticism for not only its surveillance activities of Bangladesh citizens but also for the hundreds killed in the crossfire of its official actions.

 American officials clearly have vaster and even more lethal resources at their disposal to deal with those with whom they disagree. But who or what will be the collateral damage?

 When we return to our homes overseas, will we change dramatically? Should we and everyone else “overseas,” those of us who are “foreigners,” look over our shoulders constantly, worrying about Uncle Sam snooping on us or deciding with who and how we communicate makes us dangerous or a threat? Should we look twice now, with mistrust, at the amazing technology developed in the United States at companies like Facebook, Google and Yahoo, knowing that vast amounts of online data gets scooped up and analyzed somehow by secret, out-sourced American agents?

 The waters run cool and fast into two pools at the base of the Twin Towers. It’s a great spot, along with the other planned and surrounding 9/11 memorials, for visitors like me and for millions of Americas to pause and to think deeply about tragic circumstance and unintended consequence.