How did innovations in engineering most contribute to the lasting survival of the Roman Empire?

They helped the empire create alliances.
They helped the empire spread its culture.
They helped the empire expand its territory.
They helped the empire build a stronger military.

because of the war the westeners befriended japan and each other advance.

we can argue that appeasement caused world war ii because it allowed hitler and the nazis to build germany’s military power until it was strong enough to fight a major war. additionally, appeasement emboldened germany, making it think the allies would never have the will to fight. this made germany much more aggressive and encouraged it to take the steps that eventually led to war.