Senator Bob Corker drafted the Iran Nuclear Agreement Review Act of 2015, which requires President Obama to submit a final agreement with Iran to both houses of Congress within five days of it being signed. Photo: Wiki Commons.

Congress is poised to decide whether to re-authorize programs run by the National Security Agency that assess patterns of domestic and international telephone calls and emails to uncover linkages with known terrorists. These NSA activities, initiated after al-Qaeda’s deadly 9/11 attacks, have played a vital role in protecting America and our citizens around the world from the still-metastasizing terrorist threat.

The NSA programs do not involve listening to or reading conversations, but rather seek to detect communications networks. If patterns are found, and more detailed investigation seems warranted, then NSA or other federal authorities, consistent with the Fourth Amendment’s prohibition against unreasonable searches and seizures, must obtain judicial approval for”¨more specific investigations. Indeed, even the collection of the so-called metadata is surrounded by procedural protections to prevent spying on U.S. citizens.

Nonetheless, critics from the right and left have attacked the NSA for infringing on the legitimate expectations of privacy Americans enjoy under our Constitution. Unfortunately, many of these critics have absolutely no idea what they are talking about; they are engaging in classic McCarthyite tactics, hoping to score political points with a public justifiably worried about the abuses of power characteristic of the Obama administration. Other critics, following Vietnam-era antipathies to America’s intelligence community, have never reconciled themselves to the need for robust clandestine capabilities. Still others yearn for simpler times, embodying Secretary of State Henry Stimson’s famous comment that “gentlemen don’t read each others’ mail.”

The ill-informed nature of the debate has facilitated scare-mongering, with one wild accusation about NSA’s activities after another being launched before the mundane reality catches up. And there is an important asymmetry at work here as well. The critics can say whatever their imaginations conjure up, but NSA and its defenders are significantly limited in how they can respond. By definition, the programs’ success rests on the secrecy fundamental to all intelligence activities. Frequently, therefore, explaining what is not happening could well reveal information about NSA’s methods and capabilities that terrorists and others, in turn, could use to stymie future detection efforts.

After six years of President Obama, however, trust in government is in short supply. It is more than a little ironic that Obama finds himself defending the NSA (albeit with obvious hesitancy and discomfort), since his approach to foreign and defense issues has consistently reflected near-total indifference, except when he has no alternative to confronting challenges to our security. Yet if harsh international realities can penetrate even Obama’s White House, that alone is evidence of the seriousness of the threats America faces.

In fact, just in the year since Congress last considered the NSA programs, the global terrorist threat has dramatically increased. ISIS is carving out an entirely new state from what used to be Syria and Iraq, which no longer exist within the borders created from the former Ottoman Empire after World War I. In already-chaotic Libya, ISIS has grown rapidly, eclipsing al-Qaeda there and across the region as the largest terrorist threat. Boko Haram is expanding beyond Nigeria, declaring its own caliphate, even while pledging allegiance to ISIS. Yemen has descended into chaos, following Libya’s pattern, and Iran has expanded support for the terrorist Houthi coalition. Afghanistan is likely to fall back under Taliban control if, as Obama continually reaffirms, he withdraws all American troops before the end of 2016.

This is not the time to cripple our intelligence-gathering capabilities against the rising terrorist threat. Congress should unquestionably reauthorize the NSA programs, but only for three years. That would take us into a new presidency, hopefully one that inspires more confidence, where a calmer, more sensible debate can take place.

John R. Bolton, a scholar at the American Enterprise Institute, was the United States ambassador to the United Nations from August 2005 to December 2006. This article was originally published by the Boston Herald.