You may have heard that Russian President Vladimir Putin takes an interest in exotic and impressive missile technologies. At his address to the Russian Federal Assembly last month, Putin raised eyebrows around the world by introducing a range of wacky nuclear-capable missiles, including a nuclear-powered—that’s right, nuclear-powered—cruise missile.

For Putin, these weapons are a source of national pride and speak to Russia’s continued great power status despite the country’s increased alienation from the West and long-running economic doldrums.

That alienation has intensified in recent years in no small part due to Putin’s decision to test the sinews of the post-Cold War order. Beginning with the 2008 invasion of parts of Georgia to the 2014 invasion of Crimea and amplified most recently in the poisoning of a former spy in the United Kingdom, Putin’s Russia is slowly testing the limits of international norms.

Amid all this, the Russian president has also swiped at bilateral arms control between the United States and Russia in the post-Cold War era, saying in October 2017 that it was time for Russia to “abandon” what he called an “obsolete agenda.” The missiles Putin showed off in March demonstrate a seriousness in this endeavor.

While Russia’s new nuclear-capable systems have received a lot of attention in recent weeks, the country’s burgeoning anti-satellite weapons have flown under the radar. One month after his Federal Assembly speech, the Russian military carried out a successful test launch of a developmental anti-satellite weapon.

Dubbed the Nudol , or PL19, the weapon has been tested at least six times since 2015. The most recent test was the first to see the missile launched from its eventual transporter, suggesting that the program is progressing.

Russia’s growing interest in the development of anti-satellite weapons raises an uneasy prospect: that Putin, in another act of norm defiance, may authorize the test of an interceptor against a live satellite in stable low-Earth orbit, repeating the disastrous step that China took in 2007 when it shot down a weather satellite.

More than two-thousand distinct pieces of debris from that Chinese interception continue to orbit the Earth at high speeds, threatening other satellites. Hundreds of pieces will remain threatening for decades.

The prospect may seem far-fetched now, but it merits serious consideration.

While a lot of what Putin showed off in March—including the Burevestnik nuclear-powered cruise missile and the super-heavy Sarmat intercontinental-range ballistic missile—are unique Russian innovations, Moscow is somewhat behind the times when it comes to weapons systems like the Nudol.

The Nudol’s interceptor missile is designed to do one thing: It’s meant to rapidly accelerate out of the Earth’s atmosphere and strike, using kinetic energy, a large object orbiting our planet roughly over the missile’s launch site.

In technical parlance, these kinds of weapons are better categorized as direct-ascent kinetic interceptors. The United States, for years, has invested billions into developing a wide range of interceptors with this kind of “hit-to-kill” technology, primarily for applications in missile defense.

It just so happens that the fundamentals of taking out a ballistic missile re-entry vehicle in space and a satellite are quite similar, even if how we commonly think about these two classes of objects might have little in common.

Satellites in low-Earth orbit (LEO) aren’t just placidly hovering; they’re maintaining their orbital trajectories by moving at speeds of 17,000 mph or more. Re-entry vehicles, meanwhile, have the distinction of coming back down to Earth.

In 2008, the United States showed how blurred these lines can be when an Aegis-equipped U.S. Navy Ticonderoga -class cruiser USS Lake Erie launched a Standard Missile-3 interceptor—originally designed for a ballistic missile defense role—to take out a falling intelligence satellite. (All it took to make that happen was a few software tweaks.)

On the flip side, China, after its infamous test of the SC19 direct ascent kinetic interceptor against a live satellite target in 2007, has taken to testing its newer and smaller hit-to-kill interceptor, the DN-3, against ballistic missile targets. It conducted a successful test of the DN-3 this February, taking out a DF-21 ballistic missile.

That Moscow is just now getting to the hit-to-kill party isn’t necessarily suggestive of a lack of indigenous capability among Russian engineers. Both the Nudol, the upcoming S-500 surface-to-air missile system, and perhaps even a revived Cold War-era air-launched missile will be capable hit-to-kill systems once deployed.

Russia’s position today, rather, is a product of a series of choices made by the Soviet Union during the Cold War. First, the Soviet and Russian missile defense systems that saw the most investment historically, have relied on nuclear warheads to take out incoming ballistic targets instead of seeking to satisfy the high precision demands of kinetic interception.

The United States used nuclear-tipped interceptors in the early heyday of the Cold War, but eventually moved away from the concept due to a range of flaws. Russia never did. Even today, Moscow’s periphery has multiple deployed nuclear-tipped 53T6 Gazelle interceptors.

The benefit of nuclear-tipped interceptors in a missile defense application is somewhat obvious: Even if you don’t hit the incoming target missile head on, a nuclear explosion near enough to the target can do the trick. That benefit, however, doesn’t lend itself particularly well to anti-satellite use. (This is all setting aside the inconvenient fact that the 53T6 is not designed to leave the Earth’s atmosphere.)

But even if Russia had chosen to convert a nuclear-tipped interceptor for anti-satellite use, it’d run into the problem of indiscriminately damaging a wide range of target satellites.

As China demonstrated in 2007, kinetic destruction of satellites in a stable orbit is bad enough given the massive debris that it left behind. A nuclear-tipped interceptor, if used in a conflict with the United States, could disable or destroy scores of satellites that have nothing to do with military applications and belong to third countries. (That’s what happened in 1962, when America detonated a nuke in the upper reaches of the atmosphere; the so-called Starfish Prime test took out at least six satellites.)

Twenty-one years later, in 1983, the Soviet Union, then under Yuri Andropov’s leadership, decided to respond to President Ronald Reagan’s announcement of the Strategic Defense Initiative—the genesis point of current missile defense activities in the United States—by, among other things, declaring a self-imposed moratorium on anti-satellite testing. That moratorium held in Russia until recently.

Fast forward to today, however, and Moscow is pushing ahead with the developing of what appears to be a capable system. The Nudol’s interception ceiling is not publicly known, but the U.S. intelligence community believes that the system was specifically developed to handle an anti-satellite mission (as opposed to missile defense).

In May of last year, U.S. Director of National Intelligence Dan Coats testified that the intelligence community assesses that both Russia and China “perceive a need to offset any U.S. military advantage derived from military, civil, or commercial space systems” (PDF). To do so, Coats said, both countries are “increasingly considering attacks against satellite systems as part of their future warfare doctrine.”

Ultimately, however, concern that Russia and China are outpacing the United States in anti-satellite technology is misplaced. The United States continues to lead considerably in the area of hit-to-kill systems overall.

Outside of the SM-3, the interceptors designed to protect the U.S. homeland from North Korean intercontinental-range ballistic missiles—the Ground-Based Interceptors at Fort Greely, Alaska, and Vandenberg, California—could eventually also fill an anti-satellite mission. (Neither Russia nor China has a comparable capability.)

Unfortunately, what the U.S. can do to adversary satellites in a conflict doesn’t solve a pricklier problem: American forces depend on satellites way more than other countries do—to guide bombs, help troops communicate, observe a battlefield, and a thousand other tasks.

The hit-to-kill problem is at least one that a multilateral treaty or arrangement could have addressed, but the window of opportunity may be too far gone. Besides, with the virtual indistinguishability of kinetic interceptors designed to take out ballistic missiles and from those that can take out satellites, there’s little chance of a good faith understanding with Moscow and Beijing, especially not with you-know-who in the Oval Office.

The one piece of good news amid all this is that China’s disastrous decision in 2007 to test its SC19 missile re-emphasized a norm against testing kinetic interceptors against satellites in stable orbit. Beijing didn’t suffer real costs, but the international opprobrium following its 2007 test has prevented others from attempting similar shows of capability. (The 2008 U.S. test was at a considerably lower altitude against a falling satellite.)

Washington should ensure that this norm persists as hit-to-kill missiles are developed elsewhere, including in Russia. Moscow’s recent disregard for international norms raises the disturbing possibility that it may consider an anti-satellite interception test. Putin’s recent bout of missile-nationalism also leaves open the possibility that an intercept test against a satellite could be framed as a display of Russian military prowess and might.

The Trump administration shows little interest in arms control, certainly when it comes to anything that might mean his nuclear weapons might not be “tippy top,” but the issue of preventing further anti-satellite kinetic interception tests should be a no-brainer for the United States. Preventing the testing of hit-to-kill weapons against satellites is far from an “obsolete agenda.”