Destroy war factory defenses is a mission in Jak 3. Torn wanted his best men send into the KG war factory with their new entry codes, thus Jak (and Daxter) were sent up to the factory with the HellCat cruiser.
The PlayStation 3 and Vita versions of this mission are related to a trophy named "I Want to Destroy!", completing this mission will reward you with a bronze trophy.
Take a minute to get used to the controls and your new weapons. The Blaster has a good firing rate while the bombs are very powerful and a have a big area of effect, despite their limited amount they do respawn slowly over time. The objective here is to destroy 16 'lamps' of sorts, with four each on the pillars on each corner of the Factory. After these you need to destroy another 16 spread throughout the Factory itself.
After that the four pillars will reveal themselves to be automated defensive turrets, they're not that powerful so just throw a bomb at each of them to destroy them. Throughout this entire mission you will be attacked by an endless amount of KG fighters and security tanks, don't bother fighting these and instead rely on your speed and maneuverability to get away from them.
You will automatically move on into the next mission after completion: "Explore war factory".