Shippers in the United Kingdom may be having déjà vu.

Remember when supply chain chaos caused a traffic jam of more than 100 containerships looking to dock in China? When 77% of ports were facing long turnaround times? When there was so much unattended cargo on railroads in the United States that thieves pilfered away and littered the tracks, causing train derailments?

When cargo is at rest, it’s also at risk. We’ve seen that evolve into stolen and damaged shipments, and the largest container port in the U.K. is growing riskier.

Because of an eight-day labor dispute at the port of Felixstowe, which handles roughly 40% of all container traffic in the U.K., cargo has been just sitting around. The operational stoppage is projected to affect $4.7 billion in goods. With dockworkers threatening further strikes, the disruption could even continue until Christmas. What’s worse, Liverpool, Britain’s fourth-largest terminal, may see a labor dispute, too.

Chokepoints like these cause supply chain overflows. The backup of cargo starts at the port and expands to nearby drayage yards, where ports can’t protect it and criminals are more likely to strike. In the U.K., soft-sided trailers are common and easier targets for thieves to break into.

As the disruptions continue, shippers are scrambling to keep cargo moving so it’s harder to steal. Let’s examine how stationary cargo became such a risk, and what shippers can do to avoid delays at stagnant ports and limit the risk of cargo being stolen.

Resting cargo Is a Sitting Duck

Supply chain delays became mainstream news at the onset of the pandemic, and one of the side effects was that criminals took notice. Just-in-time logistics isn’t working, and there’s no silver bullet to fix it. Inevitably there’s cargo waiting for the next stakeholder in a supply chain to take over operations, and thieves are getting smarter at identifying when and where cargo is stored and what’s worth stealing.

Markings on certain containers signal the most valuable goods. Thieves typically can’t get away with the entire container, but instead pilfer expensive electronic devices and ruin perishable shipments of food or pharmaceuticals. If a seal is broken on those perishable goods, they can’t be sold. When a container is sitting idle, it’s far easier for criminals to rifle through everything and determine what they want and what they should leave behind.

Take a container on a rail line. Privately owned rail operators have their own police force and no obligation to report crime, but reporting shows that cargo theft remains a large issue as organized gangs zero in on big targets. Five suspects were recently arrested in California for stealing $9 million of electronics. Authorities recovered more than $1 million in goods and $250,000 in cash, leaving shippers still at a huge loss.

Movement and Visibility Limit Risk

Cargo is safest when it’s moving. If you can schedule your shipments with the smallest window between pickup and delivery, you’re giving yourself more control.

But an efficient supply chain is about more than just optimizing the shipping schedule. You need to be agile so you can get in front of delays you know are coming. For instance, it’s too late now if you have a shipment sitting at Felixstowe, but if you have visibility into exactly where your cargo is, you may be able to make a change and re-route before it gets to Liverpool, which could soon go dormant.

When those disputes end and the floodgates open again, there will be a capacity strain on every stakeholder from the port to final destination. Drivers, warehouse space and secure areas to store cargo will all be at a premium, and supply chains won’t be operating smoothly just yet. In other words, the risk won’t vanish when operations resume.

You can limit risk by gaining visibility into your shipments with trailer tracking or sensors. The more visibility you have, the lower you can get your risk, because you’ll be able to make informed decisions. Some chokepoints, like a ship blocking the Suez Canal, are unpredictable. If you know that others are coming, such as a weeks-away labor dispute, and you have visibility into where your cargo is, you might be able to avoid the delays that have wounded the reputation of our supply chains.

Danny Ramon is intelligence and response manager at Overhaul.