NATO should prepare to make a stronger statement that Vladimir Putin cannot prevail in his bid to extend Russian dominance over Ukraine. In the process it can better support relief efforts in response to the humanitarian crisis the invasion created.

The international unity in opposing Putin’s war has been impressive, including wide-ranging and severe economic sanctions and supplying Ukrainian forces with weaponry that has been instrumental in their success in blunting Russian attacks.

Putin badly miscalculated in anticipating Ukrainian resistance would quickly crumble and that Russia could install a puppet government after capturing Kyiv. Instead, Russian forces suffered major losses in equipment and large-scale casualties before abandoning, at least for now, the effort to take the capital.

But like any tyrant, Putin cannot admit being wrong. He needs more incentive to find a way out.

This week Russian forces began a new offensive in eastern Ukraine with the goal of seizing control of the industrial Donbas region and the Mykolaiv region to the south, with the ultimate prize the Black Sea port of Odesa.

How should NATO respond? Continuing to supply Ukrainians with advanced weaponry and the training to use it, as now planned, should certainly be part of the strategy. And remaining unified in upholding the sanctions is critical.

Ukrainian President Volodymyr Zelenskyy has cautioned that additional help is needed and repeatedly asked for a more aggressive response — NATO imposing a no-fly zone over his country, blunting the Russian advantage of air-force dominance. NATO leaders have been correct in not doing so. A necessary step in enforcing a no-fly zone would be attacking Russian anti-aircraft positions, quickly bringing NATO and Russian forces into direct conflict, with the potential for that conflict to rapidly escalate.

But there is more NATO can do short of imposing a no-fly zone. It could create a safe, no-conflict zone in western Ukraine. Several foreign-policy strategists have advocated such an approach, chiefly Ian Brzezinski, a senior fellow at the Atlantic Council’s Scowcroft Center for Strategy and Security. The son of former National Security Advisor Zbigniew Brzezinski, he previously served as U.S. deputy assistant secretary of defense for NATO and Europe policy.

NATO, at the invitation of President Zelenskyy, could move forces across the Polish border in what it would declare a purely defensive, humanitarian move. NATO forces would only respond if Russia attacked this region, hundreds of miles from Russia’s military offensive in the east. Given his military’s poor performance, and its need to concentrate its forces in the east, Putin would be foolhardy to attack.

This safe zone would facilitate international relief efforts to help the refugees who continue to flee the conflict, allowing some to relocate safely within Ukraine’s borders and allowing better coordination for aiding those seeking refuge in neighboring countries.

It would send the signal to Putin that he should not have any pretenses about seizing all of Ukraine, not without displacing NATO from the safe zone. Additionally, it would give western nations greater leverage in the diplomatic talks that will be necessary to end this conflict and find Putin a face-saving exit that would allow him to claim some achievement for his ill-begotten gambit.

On Monday, Russian airstrikes hit the Ukrainian city of Lviv in this western territory. Located far from the new battle lines, this attack, which included destroying a car-tire factory, had little, if any, military value. Instead, as so many of the Russian attacks, it appeared an effort to terrorize civilians, including those who had fled to the western region for safety. In creating a safe zone, NATO would be saying that is unacceptable.

Yes, we recognize such an approach would bring the risk of conflict escalation. But western nations cannot allow that fear to allow Putin to dictate all the terms of how this conflict plays out. Declaring and enforcing a no-conflict zone is an idea that deserves serious discussion.