With the Battle of Kursk, another of Russia’s “red lines” was broken.

Three weeks ago, the Ukrainian military launched Shocking operation Bringing the Ukrainian war back to the territory of the country that started it. Three weeks later, Ukrainians still occupy hundreds of miles of territory in the Kursk region of western Russia.

The invasion had several goals: to force Russia to transfer troops from Ukraine to defend its towns; to seize territory that could be used as leverage in future peace talks; and to send a political message to Russia’s people and leaders that they cannot escape the consequences of the war that Russian President Vladimir Putin started two and a half years ago.

But there is another, less obvious purpose: Kiev’s leaders may hope to send a message to their friends in the United States and Europe that they are too cautious about war—that concerns about “escalation,” “red lines,” and the use of nuclear weapons by Russia, a threat that Putin himself has repeatedly voiced, are exaggerated.

Ukrainian President Zelensky explicitly acknowledged this in a statement August 19th speechsaying, “We are now witnessing a major ideological shift, that the naive, imaginary concept of the so-called ‘red line’ refers to a place near Suja” – a town now close to the border. Under Ukrainian military control.

He also confirmed that Ukraine had not informed its Western partners of the operation in advance, expecting them to be told that “it was impossible and would cross Russia’s strictest red lines.” NewsThe Ukrainians predicted—correctly, it turns out—that the West would not object too strongly once the fait accompli was established.

“They are trying to push the boundaries with their Western partners, and what we are seeing is that these partners have quietly accepted the new boundaries,” said Liana Fix, a fellow at the Council on Europe and Foreign Relations. In particular, they want the United States to lift restrictions on using U.S.-supplied long-range missiles to strike deep into Russia, a step Washington has so far avoided.

In retaliation for the Kursk’s incursion, Moscow launched a Largest Missile and Drone Barrage Since the outbreak of the Ukrainian war, the United States has been taking more military action against Ukraine. But this is far from the level of nuclear escalation that Putin often threatens.

In his speech, Zelensky effectively argued that he had called Putin’s bluff and that Ukraine’s allies should now be more proactive in providing Ukraine with the support it needs to win the war.

Since Russia’s full-scale invasion in 2022, Ukraine’s Western supporters, including the United States, There are two priorities: Preventing a Russian victory and avoiding “escalation” — that is, preventing Russia from engaging NATO forces in direct combat or, in a worst-case scenario, using nuclear weapons. Sometimes, the second priority takes precedence over the first.

The Russian government has indeed done its best to add uncertainty to Western leaders’ nuclear plans. From the first day of the invasion, Putin has repeatedly mentioned that Russia has the largest nuclear arsenal in the world, and warn These countries have brought upon Russia “consequences you have never faced in your history.”

During the war, Putin and other Russian officials repeatedly mentioned that “Red LineThis is a line that Western governments should not cross if they do not want to face a catastrophic response. Former Russian President Dmitry Medvedev was particularly active through his Social Media Accounts.

This is not all talk: the Russian government has already taken the following measures Transferring some nuclear weapons To Belarus and Conduct realistic exercises The use of tactical nuclear weapons – appears to be intended to remind Ukraine’s allies of Russia’s capabilities.

“Apart from North Korea, Russia is the country that threatens to use nuclear weapons the most,” said Nicole Grajewski, a fellow in the Carnegie Endowment for International Peace’s nuclear policy program.

These threats do work, but only to a certain extent and for a period of time. Fear of escalation is the reason why Western countries refuse to take the following actions No-fly zone established in Ukraine Or send NATO troops into the country.

Escalation concerns have also made them reluctant to provide Ukraine with certain weapons systems, although this hesitation has faded over time. Considered too provocativeNow, Ukrainians are using Long-range missiles provided by the United States and recently received their The first batch of F-16 fighter jets.

These capabilities are often provided only after months of intense political debate, much to the frustration of Ukrainians.

“I’ve been hearing about the nuclear escalation since day one,” said Oleksandra Ustinova, a member of Ukraine’s parliament and chairwoman of the committee overseeing arms supplies. Last June, he told Vox“First it was ‘If Ukraine gets MiG missiles from Poland, he will use nuclear weapons.’ Then it was the HIMARS rocket artillery system, then the Patriot missiles, then the tanks.”

She added: “It’s like we’re running behind a train. Every time we ask for something, it comes months or a year later and it doesn’t turn out as good as it was before.”

None of the steps taken by Western countries so far have resulted in Russia using nuclear weapons or directly attacking NATO countries, which many Ukrainians and their international supporters see as proof that those threats were never real.

If anything could be considered crossing a “red line,” one would think it would be the first military incursion into Russian territory since World War II.

Russian Official nuclear doctrine The use of nuclear weapons is permitted in the event of a “threat to the survival of the nation”. Occupy hundreds of square miles of territorymay not pose a direct threat to the Moscow regime, but it certainly threatens the regime’s ability to defend its territory and sovereignty – a fundamental function of any state.

Furthermore, the Ukrainians appear to be taking advantage of There are weapons supplied by the United States in Russiaobviously Violation of U.S. policy(The Biden administration agreed in May to allow Ukraine to use U.S. weapons A limited strike against Russia, It is only to defend against an attack on Ukraine.

Yet Putin and the Kremlin have issued few threats since the Kursk operation began. The president downplayed what he called “Massive provocation” and went on several seemingly unrelated trips, seemingly in an effort to give off a semblance of normalcy.

Russian media reports are a bit more mixed: Vladimir Solovyov is the host of the flagship pro-Kremlin talk show Sunday Evening, Use a Monologue called on Russia to “cool off a bit” about the invasion and called for nuclear strikes on European capitals.

Whatever Solovyov says, it does not appear that Russia intends to use nuclear weapons, attack NATO countries in response to Kursk, or go further and — as we saw with Monday’s massive shelling — destroy more Ukrainian territory with conventional weapons.

But that doesn’t mean Ukraine’s supporters are ready to take action.

exist Friday Press ConferenceVox asked John Kirby, a U.S. national security spokesman, whether Zelensky was correct that it was time to move past the fear of escalation.

“We have been concerned about escalation risks since the beginning of the conflict, and that will not change,” Kirby responded. “We are always concerned that aggressive behavior in Ukraine could lead to escalation on the European continent.” He added, “It is too early to know what impact what happened in Kursk … (might) have on escalation. But we remain concerned about it.”

As Pentagon deputy spokeswoman Sabrina Singer said recently, the administration’s thinking seems to be that “just because Russia hasn’t responded to something doesn’t mean they can’t or won’t respond in the future.” Given that we’re talking about nuclear weapons, this risk has to be taken seriously.

“Even if there’s a 10% or 5% chance that they actually do this or plan to do this, that’s enough to be worrisome,” Carnegie’s Grajewski said.

Pavel Podvig, senior researcher on Russia’s nuclear arsenal at the United Nations Institute for Disarmament Research in Geneva, believes that “this question of red lines is actually very misleading and not helpful at all.”

He believes that nuclear weapons have little military use inside Ukraine and that, given the catastrophic risks involved, Putin is unlikely to consider using any form of nuclear weapons unless the existence of the Russian state is threatened. “Technically, even the loss of a region like Kursk is not a loss,” Podvig said.

Yet Putin has certainly hinted that his threshold for escalation is much lower. Just last May, for example, he warned Western countries not to allow their weapons to strike Russian territory. Say they should “Bear in mind our balance of power in the sphere of strategic weapons.” (“Strategic,” in this case, is a euphemism for nuclear weapons.) These threats are increasingly difficult to take seriously.

Kiev’s current move is to get the United States to lift restrictions on using U.S.-supplied long-range missiles to strike deep into Russia, which would allow them to push the Kursk offensive further and hit more Russian military targets than they can currently with domestically produced weapons.

“Ukraine is only one decision away from stopping the advance of Russian troops on the front lines, and that is waiting for our partners to make a decision on long-range capabilities,” Zelensky said in his speech. Ukraine’s defense minister tweeted after Monday’s attack This attack shows Why “Ukraine needs long-range capabilities and the removal of restrictions on strikes against enemy military facilities.”

If this debate follows the trajectory of previous ones, Washington will ultimately give the Ukrainians what they want. While the risky invasion of Kursk may provide Ukraine with more ammunition in future debates, Western leaders will not easily abandon caution and give Ukraine everything they want.

As Fix of the Council on Foreign Relations puts it, the West’s “red lines” for aid to Ukraine have clearly shifted. The problem is, “We don’t know how Putin’s red lines have shifted.”