Shouting "Fire!" at a crowded border crossing

For many years, there has been a cooperative agreement between the United States and our neighbors to the north, Canada. This agreement has involved any number of things, such as sharing sports leagues, mocking each other over the relative value of currency, assisting with emergencies, and an active comedian import/export trade. And things have worked smoothly, for the most part (admittedly, a hitch in things came a few years back in September, but we offered to purchase more syrup and watch more hockey, and everything was okay again), up until a recent incident.

While rushing to assist the United States with a fire in upstate New York, a Canadian firefighting team was stopped. At the border. To check their paperwork.

So let's take a moment to make sure that we understand exactly what's happening. While we can't do anything to keep people from crossing our borders to the south (short of erecting some chain-link fencing, and encouraging people with guns to go for long walks), we actively stop emergency response teams from Canada? Are we concerned that they're going to come here, help fight our fires, and then talk at great lengths about the glories of curling? Are we afraid that after helping our own firefighters, they're then going to brag about fatback? Maybe we're concerned that they're going to reclaim Mike Myers and Jim Carrey (actually, at this point, Canada can have them back whenever they want. We'll even toss in Dane Cook).

We can understand the desire for heightened security, especially in this permanently orange-threat world. But said security shouldn't be near its highest efficiency when dealing with emergency personnel.

After all, if they can't stop Toronto fans or the import of Molson Ice, what can they do?