Current policy strongly prohibits the Army from ordering small quantities of spare parts with short notice. That currently acts as an Achilles heel for their Abrams tank fleets.
The National Interest on MSN

Why has the M1 Abrams tank lasted so long?

Despite the Abrams tank’s advanced age and increasing vulnerability to threats such as drones, it has been kept relevant on ...
LIMA, Ohio -- On Wednesday, Oct. 4, members of the Joint Systems Manufacturing Center workforce celebrated the delivery of the next iteration of the iconic Abrams Main Battle Tank as the Army accepted ...