The United States made a major tactical mistake in the war in Ukraine, according to renowned historian Niall Ferguson, Focus reported.

The longer a war goes on, the harder it is to end it. And it gets harder every week, says Niall Ferguson, a well-known Scottish historian who is now a professor at Harvard University and the author of many best-selling books on political and historical topics.

Putin bought time to change his strategy, and instead of taking Kyiv and occupying all of Ukraine, he focused on the Donbass. Now Russia is waging a war of attrition without a ceasefire, Ferguson said.

According to him, a big problem is the question of future support from the West, primarily from the United States.

He noted that the West is already feeling war-weary. The Joe Biden administration has done nothing to end this war early, Ferguson said. He noted that Washington believed that they would harm Putin if the war lasted longer. However, these calculations did not come true, as well as the hopes for Putin's departure or even for a palace coup.

The historian also does not believe that Russia will surrender because of the sanctions.