The trench warfare and heavy artillery on Ukraine’s battlefields in 2022 don’t look much like the war by air and sea that began when the United States and Israel attacked Iran.

But similarities between the two conflicts soon became evident and remain so almost three months later.

In both, the country with the more powerful military has been unable to vanquish its adversary. President Vladimir V. Putin of Russia expected a quick victory when he launched his “special military operation,” more than four years ago. President Trump initially vowed that the “little excursion” against Iran, which started on Feb. 28, would last four to five weeks.

“For both Russia and for the United States, there’s a lot of unmet expectations about their military operations,” said Nicole Grajewski, an expert on Iran and Russia and a professor at Sciences Po, the elite social sciences university in Paris, attributing it to “the hubris on both sides.”

Over the last several days, negotiations have produced progress toward an initial plan for peace between Iran and the United States, though with much uncertainty, given the renewed American strikes against Iran on Monday. Whether or not an agreement is reached, the war will have provided lessons, along with the conflict in Ukraine, on the evolution of modern warfare.

Technology reshaping warfare

Asymmetrical tactics have helped both Ukraine and Iran hold off stronger forces with which they could not compete in a conventional miliary confrontation.