Complex sentence: Iran, 3x the size of Iraq and with 3x the population had to rely purely on sheer numbers as they lacked good equipment because the US wasn't supplying them anymore and they where not yet self-suficient.
Split into simpler sentences: Iran, 3x the size of Iraq and with 3x the population had to rely purely on sheer numbers. This is becasue Iran lacked good equipment due to the US was not supplying them anymore and they where not yet self-suficient.