The recent spate of “lone wolf” terrorist attacks both here and in Canada seem to have come out of nowhere. And it’s clear that they have left Americans and Canadians as sitting ducks.

Simply by using the Internet, ISIS has encouraged “lone wolf” individuals. These “wolves” have initiated attacks on their own with no planning or coordination with others and without leaving a trail of clues about their intentions. Law enforcement authorities and our government are not well suited to defend against such individual terror strikes. As Israel has learned about such attacks, there are just too many targets to defend.

So what can be done to protect public safety? When police and the military can’t be everywhere, the last line of defense is having more citizens carry guns.

[pullquote]

Just look at the alleged lone wolf attacks in the last few months. A clear pattern seems to be developing: from the beheading a month ago in Oklahoma to last week’s car attack in Quebec, the shooting at the National War Memorialin Ottawa, and the hatchet assault in New York City. Jerusalem last week also experienced a similar Jihadist attack, with a terrorist driving his car onto a crowded sidewalk.

More On This...

The announcement Wednesday that the federal government is beefing up security at federal buildings misses the real problem: as we’ve already seen in the last month, there are an uncountable number of targets. Publicly announcing beefed up security at federal building simply makes it more likely that other targets will be hit.

After the attack on Parliament, Canada rushed to give more detention and surveillance power to security agencies. Not only is such a move more costly, but lone attackers may not send incriminating emails that alert law enforcement and that they can intercept. In addition, the approach ignores a crucial problem. What should be done if security measures fail?

The attack in Ottawa illustrates the limits to preventive policies. Michael Zehaf-Bibeau's long criminal history, including robbery, violent threats, and various drug offenses, made it impossible for him to buy a gun legally, yet he still got one. He had also flown under the government’s radar and avoided being on their high-risk watch list.

Screening people is hardly perfect. In the U.S., many politicians have pleaded for more spending on mental health to prevent mass public shootings. After all, about half of these killers have exhibited mental illness before their attacks, though very few of even those with schizophrenia – many fewer than 1-in-100,000 – represent a danger to others.

Indeed, it’s very common for mass killers to already be seeing psychiatrists who fail to identify them as threats to others, including Elliot Rodger (Santa Barbara), Ivan Lopez (the recent Fort Hood shooter), Adam Lanza (Sandy Hook elementary), James Holmes (“Batman” movie theater), and Seung-Hui Cho (Virginia Tech). There is even an entire academic literature on psychiatrists’ inability to identify these attackers.

Other countries have learned some valuable lessons on terrorism. Possibly the most important one is that terrorists determine the place and timing of their attack.

For decades, Israel responded to terrorist attacks by putting more armed police and military on the streets. Unfortunately, a mass killer can either wait for officers to leave the scene or kill them first. Israel found that no matter how much money they spent, terrorists patiently waited until a good opportunity presented itself.

Almost 15 percent of Israel’s adult Jewish civilian population has been licensed to carry weapons. With possible victims carrying concealed handguns, the would-be lone wolf attacker doesn't know who is able to defend themselves and doesn't know whom to attack first. Terrorists have to resort to less effective, secretive routes of attack such as bombing.

Killers seek out places where victims are sitting ducks.

Elliot Rodger, who shot to death three people in Santa Barbara this summer, explained why he picked his target. His 141-page "manifesto" makes it clear that he feared someone with a gun would stop him before he could kill enough people.

A mass public shooter in Canada this summer, Justin Bourque, also understood this. On his Facebook page, Bourque posted comics poking fun at how gun-free zones. One depicted a completely defenseless victim pleading with a man pointing a gun at him: "But wait ... there's a GUN BAN in this city ... you can't do this, we passed a law!" The gunman is shown thinking to himself: "Great, another one of these fruit loops."

Since at least 1950, virtually all the mass public shootings in the U.S. and all the attacks in Europe have taken place where guns carried by civilians are banned.

Canada might at least start with letting police carry guns while off-duty. When they travel around town, cops could provide a quick response to any attack. These individuals are trained and they are trusted to carry a gun while they are on duty, but somehow a minute after their shift ends they are no longer considered competent. With almost 70,000, they won’t cover most targets, but it would still be a start. Those who have served in the military should also be considered.

In the U.S. at least 12 million Americans have concealed handgun permits (see charts here and here). Indeed, in September the Oklahoma terrorist attack was stopped from beheading a second victim because a concealed handgun permit holder, Mark Vaughan, was able to quickly shoot the terrorist.

However, much more can be done. In some states, such as California, virtually no permits are issued. For instance, in Los Angeles, just a couple hundred permits have been issued to an adult population of almost 8 million.

Giving government security agencies more power may help, but it isn’t a panacea and it risks others losing their privacy. When that fails, letting people defend themselves would provide another line of defense against any attacks.

John R. Lott, Jr. is a columnist for FoxNews.com. He is an economist and was formerly chief economist at the United States Sentencing Commission. Lott is also a leading expert on guns and op-eds on that issue are done in conjunction with the Crime Prevention Research Center. He is the author of nine books including "More Guns, Less Crime." His latest book is "The War on Guns: Arming Yourself Against Gun Control Lies (August 1, 2016). Follow him on Twitter@johnrlottjr.