Major cities will likely be hit hard by the Russian aggression in Ukraine.

Retired U.S. Army Colonel Jack Jacobs stated that despite fierce Ukrainian resistance, Russian forces are encircling cities and resorting to artillery to bomb them.

Jacobs stated that the Russians will increase their indirect fire against population centers, especially Kyiv. Direct fire is weapons that aim not at a single target, but an entire area such as a whole city. Artillery pieces, such as weapons like artillery, are often used to destroy large areas.

Jacobs stated, “And in that, they’re going do something that… they didn’t want to, because they wanted the city intact.” To subdue the Ukrainians, they will use rocket launch capabilities, artillery and missiles, as well indirect fire. Then, they’ll try to get in.”

This is when the war shifts from one that plays on the Russian military strength to one that plays onto the Ukrainians’ strengths. It will also prove to be more dangerous because it is fought in urban settings.

Russia’s military culture focuses training on operations in open terrain, Jacobs said, whereas the Ukrainians — including many of its civilians — have long been preparing themselves for a door-to-door fight in the cities themselves.

Jacobs said that the Ukrainians knew from the very beginning it would come down ultimately to their ability destroy Russian forces in built-up areas. He was an officer in Vietnam War and had been involved with urban fighting.

John Spencer is an expert in urban warfare and serves as the Modern War Institute’s Director at the U.S. Military Academy. told NBC NewsOnce large numbers of Russian soldiers were in cities, things could get very ugly.

Spencer said to NBC, “The Russians won’t be able o take Kyiv just by bombing them.” “They will have to put soldiers there.”

Russian President Vladimir Putin has already demonstrated a personal willingness to destroy a city — even within Russia’s borders — if that’s what it takes to achieve his political goals.

Putin, Russia’s prime minister in 1999 launched a violent military campaign against Chechnya as a way to maintain control over the province. In the end, Russian troops destroyed Grozny’s capital. There, thousands of civilians died.

Jacobs indicated that Putin would have trouble walking the back. Jacobs said, “He will keep on going until he achieves it… even at a great cost.” Ukraine, Russia, or perhaps allies.

According to reports, other major cities of Ukraine may be already being surrounded by Russian troops. U.K. Ministry of Defence updatePublished Tuesday.

The ministry stated that while Ukrainian forces still hold Kharkiv and Kherson, Mariupol are likely to be encircled now by Russian forces.

According to NBC News, the Ukrainian government stated Tuesday that Kharkiv was its second largest city and that Russian forces were intensifying their shelling. This city hosts approximately 1.5 million people.

Russian rockets struck Kharkiv’s center on Tuesday, killing at least 10 and injuring 35 others. Anton Herashchenko, an adviser to the Interior Ministry said this in a social media post.