Complex sentence: Like the first conflict, the second war involved several skirmishes that proved costly to the Roman military who, facing large numbers of allied tribes, struggled to attain a decisive victory, resulting in a second temporary peace.
Split into simpler sentences: Like the first conflict, the second war involved several skirmishes that proved costly to the Roman military. Faced with large numbers of allied tribes, the military struggled to attain a decisive victory, resulting in a second temporary peace.