Two weeks ago, the world reacted with palpable shock to the news that Russia had unilaterally closed naval traffic through the Kerch Strait separating the Black Sea from the Sea of Azov, but it’s a mystery as to why. Moscow’s brazen violation of Ukraine’s maritime navigation rights and its arrest of sailors is only its latest egregious attack on international norms. Such attacks have ranged from the invasion and annexation of sovereign territory in Europe to the active support for the starvation of Syrian civilians. This last offense against responsible statecraft was comparatively modest, but it was no less dangerous. If Russia’s provocation was a calculated effort designed to gauge how the world would react to another transgression against Ukrainian sovereignty, Moscow got a rather definitive answer: it wouldn’t. Russia has taken its cues, and it may be preparing for something far worse.

Andrey Illarionov, a former economic advisor to Vladimir Putin who has become a fierce critic of the Russian regime in his current role as a Cato Institute scholar, told the Kiev Post this week that time is not on Russia’s side and the Kremlin knows it. Occupied Crimea is running out of water. The peninsula relies primarily on a Soviet-era canal to channel fresh water from mainland Ukraine and, between periodic draughts and the Ukrainian government’s efforts to choke off resources to the illegally occupied territory, Illarionov believes it’s only a matter of time before the canal runs dry. He thinks that Putin is resolved to prevent that kind of a crisis by any means necessary.

“He has a window of opportunity between the end of the G20 summit just held in Argentina and March 31, the presidential election in Ukraine,” Illarionov told the Post. Putin may be operating on the assumption that Ukraine’s domestic politics have paralyzed Kiev, and the international community’s collective inaction in response to the Azov incident has encouraged Russia to act sooner rather than later. That action could take the form of another military provocation, but this time on a much larger scale than the November 25 incident.

According to Ukrainian media, commercial satellite imagery shows that Russia is augmenting its troop presence both on the country’s Eastern border and in Crimea. Kiev reports that several heavy military cargo planes used to transport troops and heavy weaponry have recently flown into a Russian airbase on the peninsula. That same airbase was reinforced last week by Russia’s advanced S-400 surface-to-air missile systems. Armored infantry vehicles and personnel carriers were also reportedly spotted by observers entering Crimea over a newly completed bridge linking the occupied peninsula to the Russian Federation. Additionally, private analysts report the rapid expansion of Russian battle tanks, trucks, and supplies at facilities near Ukraine’s border with Russia. Illarionov believes this troop buildup may be a prelude to a larger strike inside Ukrainian territory aimed at securing the canal, but there is no guarantee that a Russian military incursion would end there.

Russia does not want a broader conflict with Ukraine, and it certainly does not want one with the West—that is a conflict it would lose, though not without inflicting catastrophic damage on its opponents. For its part, the West, too, is risk-averse. It has proven unwilling or unable to impose costs on Russia substantial enough to make reckless military incursions into the Near Abroad prohibitive. It should be clear by now that Russia cannot be deterred by even a relatively robust economic sanctions regime. Multilateral diplomatic engagements like those that produced the Minsk Protocols cannot offer Russia carrots that suffice to sate its territorial ambitions. If, in the coming weeks, Russia engages in a third land grab in as many American presidencies, that should be enough to demonstrate that the last two decades of Western policy toward Russia has been a spectacular failure.

To its credit, the Trump administration has tentatively embraced an alternative to the failed carrots-and-sticks approach: old-fashioned, hard-power deterrence. The United States is pressing NATO allies to commit to the deployment of air, land, and naval units nearer the Russian border—units that would not be sufficient to repel a Russian assault but would act as a “tripwire” that could trigger the broader conflict Russia wants to avoid. The only problem with this strategy is it all but cedes non-NATO allies like Ukraine and Georgia to the Russian sphere and subjects their populations to Russian aggression. That is not a recipe for a stable Europe or protection against the risk of a runaway conflict that would eventually draw the United States and its allies in. It is the opposite: a reckless and risky posture that all but invites Russian aggression, to say nothing of the nightmare of being compelled to respond in kind.

The only proven means of deterring Putin from risking a conflict with the West so far has been to absorb potential flashpoints into NATO, and that isn’t in the cards for Georgia and Ukraine. To accede to these former Soviet Republics’ ascension plans would be to assume their ongoing military conflicts with Russia and its proxy forces, and there is no political will in the West for something like that. But nothing is preventing Western capitals from committing rhetorically to the defense of states like Ukraine if Russia threatens their political independence.

Such a commitment would raise the costs of a full-scale Russian invasion of its neighbors to a prohibitive point. It would guarantee that Russia will continue to be bled by insurgents bearing American arms in the areas it occupies indefinitely, forcing Putin to calibrate his tactical considerations accordingly. It would also present accommodationist Western leftists poised to assume power in the next decade with a precedent they would find difficult to abandon. Putin would be tempted to test the West’s resolve to make good on its promises—surely, the Western alliance would be severely undermined if that resolve did not manifest in action when tested. But if the West did respond to a Russian test with a disproportionate response, the Kremlin would have made a suicidal miscalculation. Vladimir Putin is many things, but he is not irrational.

The wisdom of such a course of action is debatable, but what is not within the bounds of reasonable disagreement is the fact that Western efforts to contain Russia in the last decade have failed. It’s time to try something new, while the worst is still evitable.