Since the start of the wars in Europe and the Mideast, Washington’s warning to friend and foe alike has been “don’t.” Yet when Israel, and now Ukraine, defy President Biden’s diktats to play defense, they seem to make progress. 

Ukraine has long been warned against using American arms to attack Russian territory. This week its troops are moving ever deeper into the Kursk region. Kyiv’s control of nearly 400 square miles of Russian soil could prove a turning point in the war.

“Kursk is Putin’s finale, the catastrophe of his war,” President Zelensky says. 

Like Kyiv, Jerusalem was initially asked to forgo a military invasion, in this case of Gaza, and then warned to avoid parts of the Strip where it is now making major progress in decimating Hamas. At one point recently, “we were minutes away from getting” the Hamas chief, Yehya Sinwar, an IDF battalion commander, General Dan Goldfuss, told Israel’s Channel 12 News on Sunday.

“The coffee in Sinwar’s cup was still warm,” the general said. “Hamas is at a near-collapse.” 

As Iran and Hezbollah ratchet up threats to attack Israel, Mr. Biden, along with European counterparts and even Pope Francis, are begging Tehran to “de-escalate.” Specifically, they are urging both sides to, in the least, await a Thursday summit that Washington, Doha, and Cairo believe could end the Gaza war and calm the region. 

Yet Hamas’s now-uncontested leader, Mr. Sinwar, seems to relish statements from Tehran and Hezbollah that ignore such diplomacy and vow “painful” attacks on Israel. Hamas announced in a Sunday statement that it would avoid the proposed summit. Instead, it said, America must pressure Israel to fulfill terms laid out by Mr. Biden and endorsed by a United Nations resolution.

Since June, when the UN Security Council passed that resolution, the Israel Defense Force has marked several consequential victories. It killed Gaza’s top commander, Mohammed Deif, assumed control of the Gaza-Egyptian border, and killed Hamas’s political leader, Ismail Haniyeh, at Tehran. 

Much of that progress was made possible after the IDF all but ignored endless warnings against invading Rafah, which Washington claimed would worsen humanitarian conditions in Gaza. As Mr. Sinwar rebuffed diplomatic attempts to end the war and release hostages, Israel made clear it would advance its war aims, including by eliminating Hamas and seeking the release of all hostages.    

Washington showed its disapproval over Israel’s defiance by denying some arms deliveries. Yet, as the Rafah operation largely proved America’s warnings were unfounded, the administration largely refrained from criticizing the IDF’s operations. 

Even as arms deliveries to Israel were marginally reduced, America is now rushing to the region major military assets to help Israel fend off a multi-prong assault from Iran and its proxies. Kyiv might have taken note of that dynamic. It now seems to defy America’s long vow to defend Ukraine while warning it against going on offense.  

After the February 2022 Russian invasion, Mr. Biden quickly mobilized aid and made significant arms deliveries for Ukraine’s defense. Yet America took its time when Kyiv asked for offensive weapons such as advanced tanks and fighter jets. Washington eventually delivered the weapons, even as it put limits on their use, fearing an escalation that would engulf all of Europe in war. 

The Ukraine war had been in a stalemate for two years when Washington finally tweaked its objection to Ukrainian attacks on Russian soil. The trigger seemed to be a Russian military pummeling of border cities, including Kharkiv, this spring. 

“Over the past few weeks, Ukraine came to us and asked for the authorization to use weapons that were provided to defend against this aggression” near Kharkiv, Secretary Blinken said in May. As Russia is escalating, he added, “we’ve adapted and adjusted too.”

A week ago Kyiv finally received a delivery of American-made F-16 fighter jets it had asked for since the beginning of the war. Shortly afterward, Ukrainian forces launched a surprise attack on Russian soil. It is now retaking some of its occupied territory as well. Unconfirmed reports indicate that America was notified in advance of the Ukrainian invasion of Russia. Yet Washington has so far withheld an endorsement of the operation.     

As Jerusealm and Kyiv change the rules of the game in their respective wars, daring offensive moves may yet ignite the Mideast and Europe. America is warning foes against reacting too harshly. 

“We called on Iran to stand down its ongoing threats of a military attack against Israel, and discussed the serious consequences for regional security should such an attack take place,” America, Britain, France, Germany, and Italy said in a joint statement. 

Yet, decisive Israeli and Ukrainian military victories on the battlefield might shorten Mideast and European wars. They also could promote America’s interests better than begging enemies to stand down.