Ukrainian soldiers attend the assault training in May 2024. A study suggests that Ukraine could push back Russian lines with 14 more fully equipped brigades.Diego Herrera Carcedo/Getty ImagesUkraine can go back on the offensive, but it will require more troops and equipment.A RAND expert believes Ukraine can build a strike force capable of a decisive offensive.Right now, Ukraine's biggest problem isn't lack of manpower, but lack of equipment.With 14 to 21 well-equipped brigades, Ukraine could eject Russian forces from all Ukrainian territory, according to an American expert.The question is whether Ukraine can find the manpower, and whether Ukraine's allies are willing to spend the money to arm them properly.