HARSENS ISLAND -- Canada is a good golf drive from George Crown's Waterfront Shoppe, 200 yards the other side of the St. Clair River's South Channel and a quick trip across the strong current in just about any size motorboat.

The view eastward from Harsens Island is among many along the 4,000-mile U.S.-Canadian border where getting across looks easy.

On Friday, President Barack Obama and Canadian Prime Minister Stephen Harper committed to improved intelligence sharing to keep terrorist threats and other risky people from crossing the world's longest shared border -- even as the countries ease trade.

Earlier this week, a U.S. government report raised concerns about the northern border. On Harsens Island -- where cameras watch the border -- the two nations' proximity is lost on no one.

In June, a 38-year-old Israeli was spotted getting off a boat onto the island. Eyal Aharoni said he wanted to visit his father in Las Vegas. He was held for 78 days before agreeing to be deported.

In 2009, about 7,000 people were apprehended illegally crossing the border. It's unknown how many made it across undetected. No one wants to hurt trade, but security is a big issue.

"It only takes one of those people to be a terrorist," said U.S. Sen. Carl Levin, a Michigan Democrat.

U.S.-Canadian border a 4,000-mile challenge

WASHINGTON -- Dangling above the St. Clair River, security cameras scan the waters day and night, infrared images are beamed to a command post at Selfridge Air National Guard Base, where they are scrutinized for evidence of a breach of the border: a lone boat, say, picking someone up on the neighboring Canadian shore, then returning.

Last summer, a Detroit-area man was sentenced to seven months in jail after helping a 38-year-old Israeli cross the border at Harsens Island.

Last week, U.S. Rep. Candice Miller, a Harrison Township Republican and the new chairwoman of the Border and Maritime Security Subcommittee, toured the operations center at Selfridge and said the stories she heard make clear just how porous the 4,000-mile long border between the U.S. and Canada can be.

"Everything is being shipped to the south," Miller said. "We need to look at both borders."

The southwestern border gets much more attention, and that's understandable. In 2009, there were about 7,000 illegal immigrants caught crossing the northern border, compared with about 541,000 at the southern border.

But the northern border, say experts, congressional researchers and security analysts, poses a different problem: It's the longest shared border in the world, and more trade crosses it each day than any other. At the same time, its length and relative openness has made it easier for drugs, smugglers -- and, potentially, terrorists -- to breach it.

Last week, the U.S. General Accounting Office issued a report saying that U.S. Customs and Border Protection agents have secured less than 1% -- about 32 miles -- of the northern border.

U.S. Sen. Carl Levin, a Michigan Democrat, noted that the Department of Homeland Security says the biggest threat along the 863 miles of water border the Detroit sector is responsible for patrolling is "criminal organizations, including terrorists, and those that smuggle drugs and people via recreational vessels."

Few, if any, previous incidents can be tied to terrorism, but Homeland Security says it considers the northern border more vulnerable to terrorist infiltration "given the large expanse of area with limited law enforcement coverage and the presence of Islamist extremists in Canada."

"If Homeland Security has said the risk of terrorist activity is higher on the northern border ... then I don't have a basis to disagree," Levin said.

In 2007, former Alberta Crown Prosecutor Scott Newark, a security consultant, wrote in FrontLine Security Magazine about U.S. officials intercepting 400 pounds of marijuana brought into Michigan's eastern Upper Peninsula by rowboat from St. Joseph Island in Ontario.

Wrote Newark: "That could have been 400 pounds of 'missing' Russian plutonium."

Working together

Historically, the U.S.-Canadian border has been seen as safer than the southern, the Canadian government, more stable and security-minded than Mexico's. The countries have put in place cross-border security efforts in many areas, with American agencies working with Canadian counterparts.

In one called Shiprider, the two countries have done joint water patrols. Operation Channel Watch, on the Great Lakes, saw a coordinated effort to patrol waterways -- though it was limited to just six weekends in 2010, a fact the General Accounting Office said calls into question its efficacy.

"Canada has different rules and different internal security compared to Mexico that makes it harder for nefarious individuals to cross into the United States," said William Kowalski, former assistant special agent in charge of the Detroit FBI and now vice president of investigations for the Rehmann financial group in Troy. He said the northern border is far more secure than it might appear.

As the Accounting Office noted, one of the biggest problems may be that American agencies aren't always as good at sharing information among themselves.

"It is absurd," said Levin, who has already told the agencies he wants to talk to them within two weeks.

Some friction

No one is saying that there is a growing number of radicals in Canada, ready to strike out at the U.S. Both countries are known to have groups of extremists.

When asked what the level of a threat from Canada might be, Mike Perelman, codirector of the Institute of Terrorism Research and Response in Philadelphia, said he has no idea and doesn't know anyone who might.

But there have been cross-border security issues.

Canadians have long fought the mistaken impression that the Sept. 11, 2001, attackers came into the U.S. through their country.

But in 1999, a man accused of intending to bomb Los Angeles International Airport -- Ahmed Ressam -- did cross the border in Washington state.

Some officials in the U.S. say they think Canada is willing to grant refugee status to people the U.S. wouldn't. And there are cases in which the two countries have split over individuals and their connection -- if any -- to terrorism. U.S. officials seized a Canadian, Maher Arar, at a New York City airport and sent him to Syria, where he was imprisoned and tortured; a Canadian review found he had no link to terrorism. Last year, a Canadian court refused to extradite to the U.S. Abdullah Khadr, a Canadian national indicted in the U.S. on charges he supplied al-Qaida with weapons.

It's not a one-way street. The Canadian Press cited government reports that when it comes to people sneaking over the border between legitimate ports of entry, more were headed into Canada than vice versa.

"It's in the best interests of both Canada and the United States to maintain rigorous border controls, because the threat of terrorist activity in both nations is real," said Ray Locker, managing director of the Investigative Project on Terrorism, a Washington-based group that studies the activities of Islamic terrorist groups. "Since last summer, Canadian authorities have broken up plots in Ontario and Alberta, and those charged had connections in the United States. In one case, a man based in Edmonton was at the heart of a ring of suicide bombers targeting U.S. troops in Iraq and Afghanistan."

It may come down to resources -- or how much both countries are willing to spend.

But, said Newark, the former Alberta prosecutor, it's not about whether the bad guys are in one place or another.

"We have the same phenomenon you have, the Brits have, that everyone around the world has," he said.

Contact TODD SPANGLER: 202-906-8203 begin_of_the_skype_highlighting 202-906-8203 end_of_the_skype_highlighting or tspangler@freepress.com.