Every developed nation with a sizeable military is faced with an ongoing challenge: developing ways to maintain an offensive or defensive edge in a world full of rapidly advancing technologies and ever-aware covert intelligence efforts.

While the Cold War was in many ways a battle of economic investment and technological wit, the global arms race going on in today’s digital world is producing new (and sometimes terrifying) weapons aimed at swaying the balance of power on the geopolitical stage at just as fast a rate.

However, not all new weapons leverage cutting edge technology — in fact, some of the most versatile and troubling new systems are based on a combination of tried and true tech, which has been around for some time, and good old fashioned tomfoolery. Such is the case with “containerized” weapon systems.

At their simplest, “containerized” weapon systems are really nothing more than weapons built to carry everything they need to function inside a standard shipping container. At their most complex, they combine state of the art tech with existing weapons to create powerful hidden systems. “Containerized” tech is nothing new — many nations including Russia, Israel, China, and the United States have had various “containerized” weapons in their stockpile for years now. But what’s troubling about these systems isn’t their technology, but rather their use potential.

The most obvious and valuable use for containerized weapon systems would be enhancing the offensive or defensive capabilities of a large vehicle or static location. Ships with large decks like the Marine Corps‘ amphibious assault vessels or the Navy’s massive carriers could see their on-board suite of weapons bolstered by shipping containers delivered easily by using existing infrastructure. Those weapons could then be deployed, used, and redeployed elsewhere when needed.

However, a secondary and more nefarious use for containerized weapons could be the concealment of missile systems in port cities around the world. China, as an example, has such a massive export enterprise and it’s not at all uncommon for countless container ships carrying thousands of containers from China to be parked in American ports each day. It isn’t logistically feasible to visually inspect each and every container immediately, this leaves the opportunity for containers to be mislabeled intentionally, and potentially create an environment ripe for storing offensive weapons right on American shores.

“Containerized missiles give China, Russia, and its rogue state partners new options for directly or indirectly attacking the United States and its allies,” said Rick Fisher, a senior fellow at the International Assessment and Strategy Center, who specializes in studying the Chinese military.

“Shipping container missile launchers can be smuggled through ports or via highway ports of entry and stored for years in a climate-controlled building within range of U.S. military bases, and taken out when needed for military operations.”

Now, most of these weapon systems are not of the “doomsday” variety — for instance systems like Russia’s Club K container missiles are designed to engage surface ships and ground targets. These systems are self-contained and capable of using target data relayed to them from other sources, which means a Russian container ship gleaning data from Russian operatives secretly working within the United States could make for an extremely effective tactical combination, which although wouldn’t be enough to serve as part of a primary offensive, could still feasibly be a part of a broader effort.

Such an effort could be bolstered by foreign-flagged “missile merchant” ships made out of existing container vessels that could steam into port just in time to launch a bevy of strikes against nearby targets. This could allow an offensive force to establish a foothold in a port area. In fact, a piece published by the U.S. Naval institute last year proposed that the U.S. Navy does something precisely like that to bolster its own surface fleets.

“Because the expensive sensor suites will be off-hull, the cost to convert such ships to missile platforms should be modest, assuming the employment of standard Mark 41 VLS 8-cell modules or purpose-built ConEx boxes. Using standard 20- or 40-ft. long freight containers offers the advantage of several different loading systems and intermodal handling systems ashore,” the proposal read.

In the hands of groups that don’t answer to formal governments, containerized weapons would obviously pose a more immediate risk, as governments work to balance political and diplomatic repercussions with pursuits of national interest, whereas terror groups don’t. A system like Russia’s Club K, the land attack equivalent of China’s YJ-18C now being containerized, Israel’s Lora or Northrop Grumman’s containerized missiles could allow for targeted strikes against just about anything within hundreds of miles of public ports or common shipping lanes.

Because a massive global shipping infrastructure already exists, and many nations don’t delineate firmly between corporate and government interests, delivering weapons of these types to ports across the world and even shipping them to other strategic locations within foreign nations is more a question of cutting through bureaucratic red tape than anything else.

This may mean that ports all over the world may already have a few missile systems parked in their vicinity.