Ready for step two

You walk along the walls of your fort. You'd captured this fort three months ago and have just now fixed it up enough for it to survive an **** by either humans, elves, orcs, or another goblin clan.
You have built pots of boiling oil ready to dump on enemies assaulting the wall on foot, and archer towers for long range enemies.
"This is quite the sustainable area sire." Your general says to you as he does his daily rounds.
"Yes but we will need more resources if we are to survive here. Our food stores are not enough to last a long siege." You say watching the horizon for the littlest sign of an invading army.
"Speaking of that sire I had something I wished to discuss with you." You both stopped walking a turned toward each other. "We should make a tunnel under the fort for escape and for sieges." He looked at me hoping for me to indulge him further in this conversation.
"If you think it is a good idea then I trust you my friend." I said an patted his shoulder. He looked shocked as if I was supposed to make him fight for it.
You entered your room to see your son and wife talking on the bed. "Dad!" He said and tried to walk over to you before inevitably falling. You stand him up and sit on the bed next to him and his mother.
"Good to see you are trying son." You say as you give his mother a kiss and rub you hand through his short black hair.
"He gets better by the day." Hestry says as she stands up to stretch "It won't be long before he's hobbling all around this fort." She sits back down and you wrap your arms around her.
"We won't be ready for another war for years." You say still holding you wife close. "He may be ready to fight then."