By Evan Liu
U.S. Marines prepare a Navy-Marine Expeditionary Ship Interdiction System (NMESIS) for airlift during Exercise Balikatan 2025 in the Philippines. Photo: U.S. Marine Corps.
The Marine Corps wants small teams armed with sensors and missiles operating inside an adversary’s weapons range. Chinese military researchers are already studying how to counter them.
If a high-intensity conflict broke out in the western Pacific, one of the first challenges for the United States might not be getting more forces into the fight. It would be keeping the forces already inside China’s long-range strike envelope alive, connected and capable of finding targets.
For decades, the U.S. Marine Corps was closely associated with large amphibious ships and Marines storming beaches. But China’s growing arsenal of long-range precision weapons, sensors and anti-access capabilities has forced the service to rethink how it would operate in the Pacific.
The answer is a concept known as Stand-In Forces, or SIF: small, mobile and relatively low-signature units designed to operate persistently inside contested areas rather than retreat beyond the reach of enemy weapons.
The concept has attracted attention in China. A Chinese military journal article written by three naval officers and later translated by the U.S. Naval War College argued that these forces could complicate Chinese operations along the island chains, consume resources and create additional challenges for naval forces.
The more interesting question is not whether China is “afraid” of the Marines. It is why a relatively small number of troops scattered across Pacific islands might force a much larger military to devote resources to finding and neutralizing them.
Inside the Missile Threat
The intuitive response to China’s growing long-range strike capability would be to move large bases, ships and other valuable assets farther away.
Stand-In Forces follow almost the opposite logic.
The Marine Corps describes them as small but lethal, mobile, low-signature forces capable of operating persistently in contested areas. Their job is not necessarily to destroy every target themselves. They can conduct reconnaissance and counter-reconnaissance, track hostile ships and feed targeting information into a much larger U.S. military network.
Imagine a small Marine unit positioned somewhere along the first island chain. Using drones, radar or other sensors, it detects a warship and establishes its location. The Marines do not necessarily have to fire the weapon that destroys it; they may instead transmit the targeting data to another unit, a ship, an aircraft or a missile battery hundreds of kilometres away.
In that sense, these Marines can function as eyes and ears distributed across the island chain.
What the United States is trying to disperse is not only its troops, but the entire chain between finding a target and striking it.
That makes each small unit a node in a larger “kill web” rather than an isolated force expected to fight on its own.
Why Small Units Can Create a Big Problem
A carrier, airbase or large radar installation presents an obvious high-value target. Its location can be monitored, placed into targeting plans and, in theory, attacked.
A network of smaller units scattered across islands is a different problem.
Some may operate sensors. Others may control drones or carry anti-ship weapons such as the Navy-Marine Expeditionary Ship Interdiction System, better known as NMESIS. Their value comes partly from forcing an adversary to search for multiple dispersed targets rather than concentrating on a handful of major bases.
The Chinese military journal article highlighted by Defense News argued that Stand-In Forces could complicate Chinese operations around the island chains, particularly by providing long-range targeting information through unmanned systems and sensors.
That helps explain why one potential response focuses not only on destroying the units themselves, but on attacking the networks connecting them.
If the value of a Stand-In Force comes from seeing a target and passing that information to a shooter, disrupting communications may sometimes be more effective than hunting every Marine unit individually.
This turns the contest into an information fight: one side is trying to distribute sensors and communications so that the network survives even when individual nodes are lost; the other is trying to detect those nodes, jam their links and prevent information from reaching the weapons that need it.
The Hardest Question: How Do They Survive?
There is, however, a major weakness in the concept.
Logistics.
The Pacific is not a chessboard where small units can simply be placed on islands and forgotten. Marines still need food, fuel, electricity, spare parts, missiles and medical support. Once a conflict begins, the ships and aircraft carrying those supplies may themselves be watched and targeted.
The Marine Corps has acknowledged the problem. Its force-design efforts continue to emphasize mobility and sustainment for distributed forces operating across the first and second island chains, while the service experiments with new vessels, aircraft and logistics concepts.
There is another question: Can these units actually remain hidden?
Modern battlefields are saturated with satellites, drones, electronic intelligence and other sensors. A unit equipped with vehicles, radar, communications equipment and anti-ship missiles still produces signatures. Every transmission or missile launch may reveal information about its position.
Stand-In Forces therefore remain an evolving operational concept rather than a model proven in a major war. Their effectiveness would depend heavily on mobility, deception, communications resilience and the ability to resupply units without exposing them.
The same characteristics that make the force difficult to target also make it difficult to sustain.
Pacific Warfare Is Becoming a Contest Between Networks
The broader significance of Stand-In Forces has less to do with any single missile or even with the Marine Corps itself.
It reflects a larger change in how military power is being understood.
Traditional comparisons often focus on platforms: how many ships China has, how many aircraft carriers the United States operates, or which missile has the longer range.
Increasingly, another set of questions matters just as much.
Who sees the other side first? Who can move that information fastest? Who can keep communicating under attack? And who can turn a detected target into a target that can actually be struck?
Stand-In Forces are built around that logic. The goal is to connect small units, allies, sensors, drones, anti-ship missiles, naval forces and aircraft into a distributed network, forcing an adversary to confront many nodes rather than a few large targets.
Whether that network would survive a real high-intensity war remains uncertain.
But the fact that Chinese military researchers are already studying how to counter the concept points to the larger competition taking shape across the western Pacific.
The next war in the region, if one comes, may not be decided simply by who possesses more weapons.
It may depend on who can build the network that is harder to find, harder to break and faster at turning information into firepower.
And some of the most important pieces of that network may be small groups of Marines hidden on islands across the Pacific.
This article is based on publicly available military documents, official statements and open-source reporting. Assessments of future conflict scenarios should not be read as predictions.
Information and assessments in this article reflect publicly available material as of September 2026.
Written and reported by Evan Liu
Defense & Security · Geopolitics · Indo-Pacific
Originally published by Evan Liu in Asia Horizon Review on Medium.