The United States Army has finished converting its first division (the 3rd Infantry Division) to the new independent brigade system (IBS). The army has not got an official name for this yet, so lets just call it the IBS. The main difference from the older ROAD style divisions is that instead of three brigades with three infantry or armored battalions each, plus a divisional reconnaissance battalion, there are now four brigades. Each ISB brigade has a reconnaissance battalion and two battalions containing armor and infantry companies. For decades, infantry and armor battalions have each had three infantry or armor companies, plus a headquarters company and, sometimes, a heavy weapons company. But the new IBS battalions have two tank companies, two infantry companies, an engineer company and a headquarters company.
Thus the new divisions have twelve combat battalions, versus eleven in the old style division (one of the old brigades had four battalions.) The extra battalion for the IBS division came from converting the division air defense battalion to a reconnaissance battalion. A fifth combat brigade in the ISB division has aircraft and larger UAVs. All brigades will have dozens of UAVs, but most of these have not been delivered yet.
The new ISB organization has elements in it that have been suggested for decades. The major one is putting armor and infantry units in the same battalion. Its long been noted that tank battalions rarely operate by themselves, but exchange tank companies for infantry companies with infantry battalions when it comes time to fight. So, it has been suggested many times, why not organize the battalions in peacetime the way they operate in war time. Tradition and maintenance problems were the reasons most often given for not doing this. Both were bogus. The mechanized infantry companies are currently using Infantry Fighting Vehicles that are larger, and more powerful, than most tanks during World War II. All battalions have a mix of vehicles, and the maintenance people manage. They cope during wartime as well, when many infantry battalion commanders suddenly have a tank company or two to worry about.
The reorganization also moved most of the divisional artillery to the brigades, another common wartime practice that will now be a peacetime standard. Each brigade will have 16 self-propelled howitzers (two batteries of eight guns each, versus the old battalions that had three batteries of six guns each.)
Each brigade also has more supply and maintenance troops, making it easier to operate independently. Since the 3rd Infantry Division is the first to adopt the ISB organization, it will undergo many more changes as field exercises reveal things that should be changed. The final form of the ISB won't be known for several years.
The next division to undergo an ISB reorganization is the 10th Mountain Division. This is a "light infantry" unit, without any tanks and other armored vehicles. But the same organizational format will be used. The 101st Airborne Division (Air Assault) will also be converted this year, followed by the 4th Infantry Division (Mechanized) next year and then the 25th Infantry Division (Light), the 1st Cavalry Division and the 82nd Airborne Division after that.