On April 5, the United States signed a $4.75 billion contract with Poland to sell 250 m1a2c "Abrams" main battle tanks and a batch of relevant logistics and training equipment to Poland. The Polish Ministry of Defense said that these m1a2c main battle tanks will be equipped with the 18th mechanized infantry division and the 1st tank brigade of the army stationed in eastern Poland to deter the so-called "potential aggressors". Poland therefore became the first country in Europe to use the "Abrams" main battle tank. A "big order" Poland was an important member of the Warsaw Pact. After the drastic changes in Eastern Europe, Poland joined NATO and became the "bridgehead" of NATO's eastward expansion. The Polish army is the main force of NATO ground forces, with more than 700 main battle tanks, most of which are old t-72m1 main battle tanks and improved pt-91 main battle tanks, and a small number of leopard 2a4 / A5 main battle tanks. Poland once considered introducing a new generation of leopard 2A6 / A7 main battle tank and joining the 4th generation European main battle tank project led by France and Germany, but it was rejected. In 2017, Poland launched its own main battle tank project and invited many countries to bid. In this regard, some commentators pointed out that in fact, Poland not only wants to obtain advanced main battle tanks, but also hopes to take this opportunity to move closer to the United States. Therefore, Poland first chose the American "Abrams" main battle tank. On July 14, 2021, the Polish Ministry of defense officially announced that the Polish army would purchase 250 American m1a2c main battle tanks. According to the calculation that a tank battalion is equipped with more than 50 tanks, 250 tanks are equipped with at least 4 tank battalions. In the future, these m1a2c main battle tanks will replace t-72m1 main battle tanks and improve the equipment level of Polish army tank forces. Upgrade Road "Abrams" main battle tank is the main tank model equipped by the US Army at present. It has been synonymous with "heavy armor and sharp gun" since it was installed in the 1980s. M1a2c is the latest model of "Abrams" series main battle tank. It was developed at the end of 2016, delivered for trial in September 2017 and officially installed in June 2020. From the early M1 main battle tank to the latest m1a2c main battle tank, although they are all "Abrams" series, their performance has been different. The early M1 main battle tank used a 105mm linear bore gun, which was far from the firepower level of the 125mm smooth bore gun equipped by the Soviet main battle tank in the same period. Before the Gulf War, the US Army was equipped with m1a1 main battle tank equipped with 120mm shotgun to deal with the close range attack of Soviet t-72m1 main battle tank. In the late 1990s, the U.S. Army began to replace M1A2 main battle tank. This tank is equipped with a long peripheral sight and has the ability of "hunting and annihilation", which greatly improves the combat response speed. Since then, the US Army has completely changed its M1A2 main battle tank. And start the SEP upgrade plan to upgrade the tank firepower, observation and aiming, protection and other systems. After the end of the Iraq war, the US Army further launched M1A2 sepv2 main battle tank on the basis of strengthening armor protection capability. This type of tank is equipped with remote control weapon station to further improve the ability of the tank to deal with threats in the urban combat environment. M1A2 sepv2 main battle tank has not been equipped with a large number of troops, and M1A2 sepv3 main battle tank has been available. On the basis of fully absorbing the achievements of SEP project, this type of tank further upgrades the networked combat capability, solves the problem of re matching the total weight of the tank with the power system, and is equipped with a new data link. Therefore, the combat performance of the tank has been "qualitatively" improved. The upgraded M1A2 sepv3 main battle tank is renamed m1a2c main battle tank. Viewed from the outside, m1a2c main battle tank has a forward-looking infrared system and a general remote control weapon station. In addition, it can be equipped with active defense system and Signal Jammer. In terms of firepower, m1a2c main battle tank adopts improved 120mm shells, including m829e4 tail stable shelling armor piercing projectile and xm1147 (AMP) multifunctional high explosive tracer grenade. The former has a armor piercing power of 800 mm, and the latter is equipped with a variety of explosion fuses, which can hit more types of targets. It is worth noting that xm1147 (AMP) multifunctional high explosive tracer grenade is included in the purchase list of Poland. In addition, because the m829e4 armor piercing bullet core contains depleted uranium raw materials, which is restricted by the United States, Poland may purchase another armor piercing bullet with a armor piercing thickness of 550 mm, which limits the combat capability of Polish m1a2c main battle tank. Continue to improve In recent years, while withdrawing from the battlefields of Iraq and Afghanistan, the U.S. military has deployed heavy troops in Eastern Europe in order to deal with Russian ground forces with strong armored combat capability. Moreover, the US Army signed a contract with the ground systems branch of general dynamics to develop a more advanced m1a2d main battle tank. M1a2d main battle tank integrates a variety of technical equipment vital to the future battlefield, including artificial intelligence, the third generation forward-looking infrared sensor, integrated vehicle communication network, missile borne data link, laser warning receiver and more advanced active protection system, which will have stronger lethality, information and protection. According to reports, the U.S. military plans to train m1a2d main battle tanks in fiscal 2025 and upgrade m1a2c main battle tanks to the same operational level. These two tanks will deal with t-14 "Amata" and other advanced tanks on the battlefield, and plan to serve until 2050. (outlook new era)