But it's important to understand that all of Gaul was tribal. The was no unified country. These tribes were invading each other's land constantly to loot, rape, kill, take hostages, enslave, and extract tribute.
Gallic tribes had famously sacked Rome, and if Rome hadn't become so powerful they would have happily done it again. German tribes had successfully invaded Roman territory as recently as around the time Caesar was born. They were a legitimate threat, especially to the Roman province, although it's also true Caesar's had other motivations.
Again, it's just much more complicated than when for example Hitler and Stalin jointly invaded the entirely peaceful country of Poland. Or when Putin invaded the entirely peaceful country of Ukraine.
But it's important to understand that all of Gaul was tribal. The was no unified country. These tribes were invading each other's land constantly to loot, rape, kill, take hostages, enslave, and extract tribute.
Gallic tribes had famously sacked Rome, and if Rome hadn't become so powerful they would have happily done it again. German tribes had successfully invaded Roman territory as recently as around the time Caesar was born. They were a legitimate threat, especially to the Roman province, although it's also true Caesar's had other motivations.
Again, it's just much more complicated than when for example Hitler and Stalin jointly invaded the entirely peaceful country of Poland. Or when Putin invaded the entirely peaceful country of Ukraine.