With the murderous and frightful terrorist attacks in Paris just last week, once again we are reminded of the need for law enforcement and our international intelligence agencies to have the ability to anticipate and prevent terrorist attacks and to protect us.

We in Washington, D.C., feel special fear this week after the Islamic State in Iraq and Syria (ISIS) specifically declared our nation’s capital as their next target.

The question remains: Can we allow our national and international intelligence agencies and law enforcement officials to use all the tools to intercept and be able to anticipate terrorist attacks, as they have done in the past, without violating our fundamental privacy rights and civil liberties?

My answer is yes — and it has been since I was appointed to and served in 2006 and 2007 on the first Privacy and Civil Liberties Oversight Board, created in the aftermath of 9/11 and the deaths of 3,000 Wall Street workers and first responders in the Twin Towers.

The establishment of a massive surveillance program by the Bush administration after Sept. 11, 2001, allowing phone calls from known terrorists to U.S. citizens to be monitored, was found to be illegal and unconstitutional. It needed to be fixed by the U.S. Congress — and it was. Congress required more precise standards and required the Foreign Intelligence Surveillance Court to be more accountable, including having a privacy advocate sometimes involved prior to making final decisions.

I was the only Democrat on the five-member board and always considered myself a liberal privacy rights and civil liberties advocate. Another member of the board was the famous conservative Republican attorney Theodore Olson (made more famous in recent years when he joined with liberal attorney David Boies to lead the legal team that overturned the unconstitutional ban on gay marriage).

While Ted Olson and I disagreed on many things political, we found common ground when it came to admiring the work of the intelligence agency workers engaged in the surveillance and anti-terrorism programs. We saw strong evidence that their round-the-clock efforts, as well as the work of those at all the intelligence agencies and the National Counterterrorism Center, had in fact anticipated and prevented many terrorist incidents in the U.S. since 9/11. The problem, of course, is that it is difficult to prove this without revealing the sources and methods that allowed these programs to be successful.

Now we live in an era where Internet mobile phone apps have been invented and are being used by ISIS and other terrorist groups that prevent law enforcement officials from listening in on calls, even when they have a warrant and know specific identified terrorists are planning an attack on the United States.

Our current FBI director, James Comey, has repeatedly warned us that these apps are used by and facilitating terrorist attacks. But they are being defended in part by their inventors and protectors in Silicon Valley and elsewhere, who boast of having no “back door key” available — i.e., ability to be intercepted — even where known, identified terrorists are identified representing a clear and present danger of a terrorist attack and a court has issued a specific warrant.

How is this possible?

The current Privacy and Civil Liberties Oversight Board, which is supposed to protect us from governmental infringement of our constitutionally protected rights, has the most credibility to go to Congress in support of requiring such back-door keys in all such apps — but with high standards of evidence to obtain a warrant and ample protection for such keys to prevent hacking by anyone other than law enforcement with such a warrant.

We should not allow Edward Snowden, who preaches privacy rights to us from Russia (not exactly a safe haven for privacy rights), or anyone else persuade us to accept the fallacy of the false choice:  We need and can have protection of privacy rights and personal and national security.

This is the perfect purple issue for liberals and conservatives, Democrats and Republicans. We must have both. Now more than ever.

Lanny Davis served as special counsel to former President Clinton and is principal in the Washington, D.C., law firm of Lanny J. Davis & Associates, and is executive vice president of the strategic communications firm LEVICK. He is the author of the recently published book “Crisis Tales: Five Rules for Coping with Crises in Business, Politics, and Life.”