Not since the terrorist attacks of September 2001 have ordinary people been as concerned about the risk of a terrorist attack inside the United States. Since Islamic State militants began seizing swaths of Iraq and Syria and beheading Western hostages, nearly half of Americans now believe their country is less safe today than before the 9/11 attacks, according to a recent NBC poll. That's almost double the number from just one year ago.

Citing the potential for jihadists with Western passports to enter undetected into the U.S., some Washington politicians sound downright panicked. "This is a turning point in the war on terror," South Carolina Sen.Lindsay Graham told Fox News. He called on President Barack Obama to deploy thousands of ground troops to Iraq, "before we all get killed back here at home."

"They intend to kill us. And if we don't destroy them first, we're going to pay the price," said House Speaker John Boehner this Sunday. Obama's own secretary of defence, Chuck Hagel, has called the Islamic State group "an imminent threat to every interest we have." John Allen, a retired four-star Marine Corps General who formerly led the war effort in Afghanistan, declared it "a clear and present danger."

Fears were heightened when the Iraqi president, Haider al-Abadi, said on Sept. 25 that there was credible evidence of a plot by Islamic State to attack subways in New York. Police presence was beefed up in stations and Mayor Bill de Blasio rode the trains to reassure the public. Meanwhile, U.S. intelligence agencies said they had no indication of such a threat.

Whenever Americans get scared, Canadians brace for economic repercussions. The attacks of 9/11 led to security policies that critics say resulted in a "thickening" of the border that hampers commerce and trade. In the 13 years since, enormous government and corporate efforts have gone into trying to roll back, or make more efficient, the resulting wave of new security procedures in the name of keeping commerce alive. But many of the steps are permanent: from arming Canadian customs officers to a requirement that all travellers carry a passport in order to cross the international line. The border is now once again in the political crosshairs. "There is a great concern that our southern border, and our northern border, is porous and that [terrorists] will be coming across," said Sen. John McCain this month.

Full story: The return of fear on the U.S.-Canada border – Macleans.ca.