This is the M1 Abrams, the powerful American main battle tank the US is sending to Ukraine

businessinsider: The US has been sending Ukraine more and more weapons, promising Kyiv hard-hitting rocket artillery, formidable air defense systems followed by infantry fighting vehicles, and now, after some debate, it's agreed to send M1 Abrams tanks.

Senior Pentagon officials said last week the US was not ready to send these, arguing that the "Abrams tank is a very complicated piece of equipment" that is expensive, difficult to maintain, and hard to train on, but this week, the US joined partners in Europe in offering Ukraine tanks.

The British Challengers, German-made Leopards, and American Abrams are modern battle tanks with superior capabilities compared to those of the Soviet-era tanks Ukraine has relied on and provide the kind of mobile firepower and shock effect necessary to break through enemy lines and enable new offensives at a time when the front has become largely static.

An M1A2 Abrams Tanks from A Company, 2-116th Cavalry Brigade Combat Team (CBCT), Idaho Army National Guard run through field exercises on Orchard Combat Training Center (OCTC).Thomas Alvarez/Idaho Army National Guard

Ukraine's defense ministry humorously suggested renaming the Abrams a "recreational utility vehicle" to alleviate any potential US concerns about sending tanks, but this heavy tracked vehicle is a tank and one of the most capable in the world.

The M1 Abrams tank, a heavy armor product of what is now General Dynamics Land Systems but was Chrysler Defense, was developed in the 1970s as a replacement for the Army's older M60 tanks. It first entered service in 1980, but it didn't see combat until the Gulf War in the early 1990s.

Just over 2,000 Abrams tanks were deployed with combat units during the war, and only 23 were damaged or destroyed. Of the nine that were destroyed, none were lost as a result of enemy action.

A Government Accountability Office report on the performance of the Abrams tanks and Bradley infantry fighting vehicles in that conflict said that Abrams crews reported taking direct frontal hits from Soviet-era T-72s and sustaining only minor damage.

In the aftermath of the Gulf War, the US military developed the M1A2 Abrams, which has steadily been upgraded over the past two decades. The Abrams tank also saw extensive combat early in the Iraq War and was used to some extent in Afghanistan.

US Army troopers assigned to 3rd Armored Brigade Combat Team, 1st Cavalry Division fire the M1A2 SEPV3 Main Battle Tanks as part of gunnery qualification, Sept. 22, 2022, on Mielno Tank Range, Drawsko Pomorskie Training Area, Poland.US Army Photo by Staff Sgt. Charles Porter

The modern M1A2 weighs more than 70 tons, is powered by the AGT1500 gas turbine engine providing 1,500 horsepower for speeds up to 42 mph, and is armed with a 120mm main gun, a M2 .50 caliber machine gun, and a pair of M240 7.62mm machine guns.

Crewed by a team of four soldiers, specifically the gunner, loader, driver, and commander, the Abrams can deliver the mobility, firepower, and, perhaps most importantly, shock effect needed to exploit weak points in enemy lines and pursue offensive breakthroughs.

When engaging the enemy, the Abrams is protected by Chobham composite armor improved with depleted uranium meshing. Its protection can be upgraded with explosive reactive armor blocks.

General Dynamics Land Systems is currently in the process of developing the next-generation Abrams, the so-called Abrams X main battle tank, which will rely on a smaller crew supported by artificial intelligence to deliver increased combat capability with better fuel efficiency.

US Army troopers assigned to 3rd Armored Brigade Combat Team, 1st Cavalry Division fire the M1A2 SEPV3 Main Battle Tanks as part of gunnery qualification, Sept. 22, 2022, on Mielno Tank Range, Drawsko Pomorskie Training Area, Poland.US Army Photo by Staff Sgt. Charles Porter

The US has, until now, been hesitant to send these tanks, pointing to the complicated maintenance and operational difficulties.

Jeffrey Edmonds, a Russia expert at the Center for Naval Analyses and former US Army armor officer, told Insider last week that the US should do what it needs to do to get Abrams tanks to Ukraine, but he acknowledged that there are hurdles that make it a challenge.

"The maintenance problem, with all it's components, that is the real challenge," Edmonds said, pointing to the thousands of tiny parts, some of which are essential to keeping the vehicle running properly, that Ukraine has to be able to get its hands on and use in the field.

Troopers with 3rd Battalion, 8th Cavalry Regiment, 3rd Armored Brigade Combat Team, 1st Cavalry Division prepare test fire the U.S. Army’s new M1A2 SEPV3 Abrams Main Battle Tank, Fort Hood, Texas, August 18, 2020.US Army photo by Sgt. Calab Franklin

"The other thing that people don't really talk about is how well the crews will be trained and how well they use the tanks," he said, noting that "fighting in a tank is kind of an art."

But if Ukraine can maintain and operate them properly, "they're great for the Ukrainian force," Edmonds said, explaining that "the whole reason tanks were created was to make a static situation fluid."

The situation along the front lines in Ukraine is brutal, with battles turning into grinding exchanges of artillery with minimal gains on either side.

Powerful modern tanks like the Abrams, Leopards, and Challengers the Ukrainians have sought, along with all the other armor and weaponry heading that way, could be just what Kyiv needs to fuel an offensive and break through Russian lines, but that remains to be seen.

The US has said it will send Ukraine 31 Abrams tanks, as well as the equipment and parts necessary to sustain them, but it will likely be months before these arrive on the battlefield.