The New York City Police Department should be applauded, not lambasted, for keeping the city safe during the 2004 Republican National Convention. But the New York Times and the American Civil Liberties Union just can’t pass on so tempting a target as intelligence gathering, it seems.

To self-proclaimed defenders of “civil liberties,” intelligence work is necessary in the theoretical, but when the actual work gets carried out, it is almost always characterized as sinister.

Take the attack on the World Trade Center: That was painted as a massive intelligence failure. Yet subsequent efforts to identify terror networks that might carry out the next September 11 are routinely portrayed as overreaching.

That thinking is compounded by a foolhardy notion moving easily among the American Left these days that goes something like this: The threat from Islamofascism was monstrously and deliberately exaggerated by conservatives to scare Americans into going to war, re-electing a president, and stomping on civil liberties, which, presumably, conservatives like doing for some reason. The evidence? No terror attacks in five and a half years.

The truth is that our enemies have never stopped trying to attack the American homeland and kill American citizens. In fact, there have been some 300 mostly successful prosecutions of terror-plotters in America in recent years, and it is the height of folly — indeed disingenuousness — to suggest that those who wish us harm have called it quits.

During the past five and a half years, moreover, American forces have been operating overseas, capturing, killing, and non-violently disrupting Islamofascist operatives everywhere they live and breathe. Perhaps that has something to do with the absence of attacks on our soil.

But also deserving undeniable credit are those on the frontlines — the home front warriors in this War for the Free World — chief among them the New York City Police Department.

The NYPD is at the cutting edge of combating terror networks and has proactively thwarted major attacks since September 11. It even assigns detectives to work overseas, in cities like London, Amman, Tel Aviv, and Toronto, to investigate possible plots being hatched there to attack us here. But the NYPD’s work — intelligence gathering in the real world — is now predictably under assault by the aforementioned civil liberties agitators, a phalanx of lawyers and their allies at the New York Times.

On March 25, the Times reported on its front page that lawsuits against New York’s Finest have produced evidence that the NYPD went to extraordinary lengths to prevent terrorist attacks at the 2004 Republican National Convention.

Specifically in the Times’ crosshairs was the NYPD’s “RNC Intelligence Squad,” which was charged during the Convention with assessing the intentions of individuals and groups — among the 800,000 protestors — who exhibited an interest in: violently or otherwise disrupting the Convention; interfering with or damaging the infrastructure, facilities, and businesses servicing it; or otherwise impinging upon its delegates’ exercise of their freedoms of assembly and speech.

This was a legal intelligence collection operation sanctioned by a federal judge, the Times noted — after the jump from page A1— specifically granting the NYPD “greater authority … to investigate political organizations for criminal activity.”

The types of tools used by the NYPD to gather counter-terrorist intelligence during the Convention were as indispensable then as they are now. The value of such assets was evident immediately after the London subway bombings in July 2005, when NYPD Deputy Commissioner, David Cohen, received a detailed briefing from an NYPD detective in London about the tactics and materials used in those attacks, the specific methodologies employed, and the names of the suspects. All of this information was then shared with officers in the field here.

The NYPD has been a national leader in recognizing that policing in an age of terror requires not only proactive intelligence collection but the ability to act decisively upon the fruits of that collection — rather than waiting for disaster to strike, and then reacting. Since New York’s Police Commissioner, Raymond Kelly, took over in 2002, he has greatly strengthened the NYPD’s capacity for decisive action.

Intelligence-led policing as practiced by the NYPD is a significant reason why we have not been successfully attacked again. Rather than hector those who are working hard to protect us while respecting our rights, denying them tools they need to do so or imposing new bureaucracies such as a British-style MI5, we should ensure that they receive our support.

Mr. Gaffney is president of the Center for Security Policy and a columnist for the Washington Times. Amanda Bowman, the Center’s New York director, contributed to this article.