Russia's Military Faces Personnel and Maintenance Shortages.

TL;DR
Russia is running out of tank crews due to the loss of experienced tankers in the ongoing war with Ukraine. To compensate, Russia is restoring and using obsolete T-55 and T-62 tanks, which are easier to operate but have slower rates of fire and are less effective in combat. Assigning new crews to old tanks is a short-term solution that may create an even deeper tanker shortage by getting inexperienced crews killed in lopsided fights with better-equipped, better-trained Ukrainian forces.
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