America’s response to the fanatical thugs who invoke Islam as a justification for mass murder requires effective law enforcement at home and the mobilization of a coalition to attack them militarily abroad.

Last week I stressed what we shouldn’t do domestically. Today I focus on what we should do.

Those entrusted with our security must be fully empowered to find, pursue and imprison would-be perpetrators of terrorist violence, beginning with the ability to use the full range of surveillance techniques necessary to thwart those who plan to do harm. I say that as one who voted against the Patriot Act after 9/11 and who joined in calling for restrictions on the mass data collection that followed.

I did so because they intruded on the privacy of the great majority of Americans for whom there was no basis for even the slightest suspicion. But I differentiate these policies from more targeted efforts to discover those who do plan violence in the name of a twisted version of their religion. Given the indisputable fact that the danger they pose to us has increased, with the Islamic State having demonstrated both the capacity and intention to export brutality beyond the Middle East, I support giving those we have charged with protecting us against them more leeway in tracking them down.

This means lowering the barriers that we correctly maintain in normal circumstances against unduly aggressive investigative methods. Specifically, we should relax the amount of information required to permit searching of physical premises, monitoring phone calls, examining emails and texts and installing microphones to overhear conversations. The use of undercover agents to infiltrate groups likely to be plotting violence should not be unduly restricted. And to be explicit about the most sensitive subject, it would be equally wrong to target mosques or other Islamic organizations without some indication that they pose a threat or to give them an exemption from these techniques if there is some basis for suspicion.

I am not calling for a free hand for law enforcement agencies to roam, physically or electronically, wherever they decide without showing to a judicial authority that they have a reason for doing so. I am arguing that given the dimension of the threat and the difficulty of uncovering the identity and intentions of fanatics who are plotting violence, the level of information they must have to justify their suspicion should not be as high as it is for normal domestic crime.

I have three points to make in justification of this argument.

First, the threat of religiously inspired domestic terrorism with strong international links presents the police – local and national – with a challenge that is both far less familiar to them and more complex. The motivations, methods of operation, behavior patterns and resources of religious fanatics vary sharply from those of the criminals with whom our law enforcement agencies usually deal. Experience gained in policing counts for less when the potential law breakers come from a very unfamiliar moral, ideological and cultural context.

Second, I believe that the record of these agencies in recent years justifies a higher degree of trust than many are prepared to extend to them, particularly at the federal level. I have joined in the sharp criticism of the racially discriminatory actions of many local police departments and I support strengthening our defenses against them. But none of these deaths resulted from unduly intrusive wiretapping, undercover agents infiltrating suspect organizations or the search of suspect premises authorized by improvidently granted warrants. The excessive use of force by police officers in specific confrontations must be curtailed, but making it harder for investigators to uncover terrorist plots does nothing to accomplish this.

There was some abusive treatment of Muslims in the immediate aftermath of 9/11. But as reluctant as many of those legitimately concerned with the protection of civil liberties are to acknowledge it, lest it lead to letting down our guard, there has not been a record of systematic law enforcement overreach in the fight against domestic terrorism since then. It is a sign of the increasing maturity of our society that we have not seen in this century the disregard for the rights of innocent people, including dissenters, which marked both World Wars, Korea and Vietnam. Having voted against the Patriot Act and opposed massive data collection, as I noted, I have been pleasantly surprised that there have been few examples of the misuse of either one of them.

There is a third reason why those eager to make sure that our values are not compromised in this struggle should support law enforcement efforts appropriate to the current challenge. The willingness of the American people to continue to welcome immigrants, including refugees from the Middle East, depends on their feeling secure that we can defend ourselves against any who would take advantage of this to perpetrate violence. We can never be 100 percent sure that no bad actors hide among the overwhelming majority of innocent victims who deserve our protection. Consequently, fully empowering those we charge with protecting us with the tools they need to do so in this very different environment is a necessary step in convincing Americans that we have an alternative to shutting our doors.

Barney Frank is a retired congressman and the author of landmark legislation. He divides his time between Maine and Massachusetts.

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