While Russia’s submersible “doomsday” drone, the Poseidon, made headlines the world over, the truth is, such a weapon offers an extremely limited range of strategic capabilities. The large unmanned submarine and its claimed 100-megaton nuclear warhead would, if detonated, unleash a level of destruction never before seen by a man-made weapon. However, it would also prompt an immediate nuclear response that would leave the United States, Russia, and the future of the world as we know it in ruins. The Poseidon truly is a “one and done” weapon, in that using it just once would begin a cascade of events that yields no winners, only devastation.

Now, the United States has revealed its own plan to begin fielding large-scale unmanned submersible vehicles, but unlike Russia’s Bond villain-style Poseidon, America’s two drone subs in development are slated to offer a broad variety of strategic capabilities meant to win a near-peer or peer-level conflict beneath the waves, without resorting to nuclear war.

This difference in approach belies a difference in methodology and funding: America’s robust defense apparatus and strong economy can support initiatives aimed at combat dominance, while Russia’s struggling economy has forced a “last resort” mindset on high-end defense initiatives. Russia knows it can’t afford to sustain, let alone win, a peer-level conflict, so it’s opted to instead remind the world millions of innocent people would be killed if Russia’s ever backed into a corner. Threatening to end the world if ever you’re confronted with overwhelming military force may sound awfully petty, but it’s also a fairly effective means of deterrence.

America’s forthcoming drone subs may not offer the doomsday punch of the Poseidon, but the two initiatives underway may well offer a glimpse into the future of undersea combat. The Navy’s Extra Large Unmanned Undersea Vehicle (XLUUV) and the Large Diameter Unmanned Undersea Vehicle (LDUUV) programs are being designed and built with a modular approach, meaning, these vessels will be able to swap out mission-related equipment and even the systems driving the sub’s primary functions with little effort or cost. That makes each platform upgradable for decades to come and allows the Navy to incorporate new defense technology more quickly, easily, and most importantly, cheaply.

“These will help consolidate Navy vision to bring UUVs (Unmanned Underwater Vehicles) and USVs (Unmanned Surface Vessels) to the fleet, and integrate them with surface vessels and submarines,” Capt. Pete Small, Program Manager for Unmanned Systems, said.

The XLUUV, commonly referred to as the Orca, is based on Boeing’s Echo Ranger design. At 84 feet long and 50 tons, it will be twice as long as a school bus and four times as heavy, with the capability to reach depths as low as 11,000 feet and an operational range of 6,500 nautical miles.

The drone is capable of obstacle avoidance and autonomous buoyancy control, meaning, it can dodge obstacles and keep itself level without any input from human operators. According to Boeing, the Orca can operate in congested waters “for months at a time” without any human input. Currently, Boeing is on contract to deliver four Orcas to the Navy, which suggests these platforms are intended not only for testing, but potentially for actual naval operations as well.

The LDUUV would offer similar mission capabilities, but with less autonomy. According to the Navy, it could be launched by either Virginia-class fast-attack submarines or surface vessels, where it would remain relatively close to its “mother ship” while providing mission support.

Either vessel will reportedly be capable of carrying Mark 46 lightweight torpedoes or even Mark 48 heavy torpedoes for engagements with submerged vessels or surface ships, and they could potentially even carry anti-ship missiles as well, making these autonomous vessels a serious threat for encroaching enemy ships.

The plan is not without its challenges, however. Operating autonomously for months, as the Orca is expected to do, may offer a great deal of strategic value in terms of reconnaissance, defensive and even offensive operations, but it also requires a robust navigation and underwater communications capability that can survive any number of forms of interference or technical difficulties. If an Orca goes offline in a Russian deep-water port, it’s important that the drone doesn’t eventually power down and just come bobbing up to the surface, after all.