Egypt's president Abdel-Fattah El-Sisi told army cadets on Sunday "information wars and psychological wars destroy nations," sate-owned agency MENA reported.
The president's remarks came during a visit to the Egyptian Military Academy in Heliopolis during early morning physical training.
The Military Academy in Heliopolis, one of several army colleges, trains future army officers and other military leaders.
He added that Egyptians should avoid such modes of conflict, and that their effects on the Egyptian youth should be studied.
The president, who returned to Cairo on Saturday after a six-day Asian tour, wore a casual sports tracksuit for the occasion.
He was accompanied by defence minister Sedki Sobhi and the army's chief of staff Mahmoud Hegazy.
All three men attended the Military Academy themselves.
El-Sisi urged the recruits to adhere to the "principles and values inherent to the Egyptian military" and to set a good example to other Egyptians.
Egypt's army is currently deployed inside and outside the country.
In North Sinai the army is battling an Islamist insurgency which has worsened since the removal from power of Islamist Mohamed Morsi.
Last February, Egypt carried out airstrikes on Islamic State targets in Derna, Libya in retaliation to the terrorist group beheading 20 Egyptian migrant workers.
Egypt's army has also been deployed in Yemen since March as part of a Saudi-led coalition fighting against the Houthi rebels.