The hittite empire was able to survive even attacks by rivals because:

The Hittite Empire was able to survive even attacks by rivals because they had iron weapons.  the Hittites were the first people to exploit this capability, who were able to defeat the armies of Ramses II in the 12th century B.C. The Hittites the were first users of iron, they began to produce iron tools and weapons around 1400 B.C.E, they tried to keep their metalworking methods secret.