Why did Roland say that Marsilla was treacherous?

Roland considered Marsilla treacherous because he believed that Marsilla's actions were deceitful and aimed at undermining the Frankish forces. Marsilla, the king of the Saracens, had feigned a desire for peace while secretly plotting to attack Charlemagne's army. This duplicity made Roland view him as untrustworthy and a direct threat to their safety and honor in battle. Roland's perception of treachery was rooted in the broader context of loyalty and betrayal in warfare.