Complex sentence: Recognizing that the problem of combining excellent mobility with heavy armour was for the time being irresolvable, the AMX 50 project was terminated; the priority given to mobility demanded a new design concept, leading to the AMX 30, the lightest MBT of its time.
Split into simpler sentences: Recognizing that the problem of combining excellent mobility with heavy armour was for the time being irreoncilable, the AMX 50 project was terminated;. The priority given to mobility demanded a new design concept, leading to the AMX 30, the lightest MBT of its time.