The recent blockade of the Ambassador Bridge between Windsor and Detroit by a group of determined protesters using heavy trucks has shed a bright light on the vulnerability of international trade between Canada and the United States. This single bridge carries a large chunk of bilateral trade, estimated as much as a quarter. It is vital link that connects the auto industries in Ontario and Michigan, which are highly integrated. The blockade was an attempt at economic coercion by blocking a chokepoint of international trade. Officers from multiple police forces cleared the bridge on February 13. Economic coercion has nothing to do with peaceful protest and freedom of speech. No group has the right to hold an entire economy hostage to further their political goals.

The Ambassador Bridge has been a key vulnerability to Canada's trade with the United States. The bridge, which opened in 1929, is owned by the heirs to billionaire Manual Moroun. There are few alternatives to this crossing for shipping. The Blue Water Bridge between Sarnia and Port Huron is about 100 kilometers away. The traffic between Windsor and Detroit is so important that Canada has started construction of the Gordie Howe International Bridge, pictured above. The bridge is being built against fierce opposition from the owners of the Ambassador Bridge. Importantly, this crossing will connect directly ho Highway 401 on the Canadian side and Interstate 75 on the US side, improving significantly on the traffic flow that was impeded on the Canadian side by traffic flowing through city streets in Windsor. The 2.5km bridge is expected to open in 2024.

Resilient international trade requires redundancy in critical infrastructure. Redundancy protects against the many contingencies that can arise. Building the Gordie Howe International Bridge, at an estimated cost of US$5.7bn, is an investment into the future that will pay off in increased economic opportunities for Canada. By the time the new bridge opens, the old Ambassador Bridge will be nearly one hundred years old. Bridges have a finite lifespan, and given the importance of crossing the Detroit River for Canada's economy, the redundancy and improvement that the new bridge provides is necessary and prudent.

The term critical infrastructure refers to assets, systems, and networks that are essential for the proper functioning of a country's economy, society, and government. Governments must act to protect critical infrastructure, whether it involves hospitals or international bridges. Illegal occupation or interference with critical infrastructure requires prompt police action to end it.

Canada's 1988 Emergencies Act identifies different types of emergencies and provides mechanisms to provide additional powers to the Federal Government of Canada for a limited time and for limited scope, with significant parliamentary and judicial oversight, and accountability through an ex-post public inquiry. Most importantly, the Emergencies Act allows Canada's RCMP to be deployed where muncipal and provincial forces are inadequate or insufficient to protect critical infrastructure, or restore public order. Unlike its predecessor, the 1988 Emergencies Act is not a political sledgehammer, but more like a surgical scalpel. Its application can be custom-tailored to the situation, while fully protecting Charter Rights. The statute was designed with many guardrails in place to protect against miuse.

Whether the Emergencies Act was invoked too late when most of the exceptional situation had already passed will be debated for some time. However, should a situation arise again where local police forces are unable to cope with blockades of critical infrastructure, the powers of the Emergencies Act should be used swiftly and without hesitation. Ultimately, the federal government will need to revisit existing legislation to determine where improvements are necessary to protect critical infrastructure against illegal blockades, without triggering the need to rely on the Emergencies Act as the last resort.

Canada's critical infrastructure deserves more attention. Canada has conducted risk analyses, where risk is measured as a combination of threat (probability of attack or incident), vulnerability (probabilty that attack will succeed in causing damage), and consequence (cost of damage). Malicious attacks against critical infrastructure are particularly difficult to prevent where infrastructure is diffuse (networks) rather than focal (points). While current attention has been focused on protecting physical assets, our virtual assets are gaining in importance because of our increasing reliance on information technology throughout the economy. Our computer networks and servers are vulnerable to cyberattacks. The federal government has taken notice and launched the Canadian Centre for Cyber Security in 2018. Hardening our critical IT infrastructure is a formidable challenge. Prosecuting cybercrimes is especially challenging when cybercriminals can conduct their offences from beyond Canada's borders. That means that the emphasis needs to be on protection and reducing vulnerability.