I was aghast at the thought of that about three years ago. Now I agree entirely with your point of view. Non lethal chemical agents first. If that fails to disperse the hordes,
Well I never served but I would think the use mortars or maybe something much longer range would be in order. Like 155mm.
Migrants in a pigs eye.
This is an invasion.
We could also force them back onto the other side of the wall, which is still US land, but give them no water or food.
They have to hike back to Mexico.