Sick trees - advice

We moved back to our property after 18 months away to find that our pine trees on the corner of our property look really sick. I've taken a pic with my iPhone, which doesn't really convey the problem unless you zoom in. The position is the least critical as I impliment our new permaculture design, but i'm trying to figure out if I should go down the 'trying to heal route' or just chop em. Any advice very much welcomed.

More information would be good....especially your location, what kind of pine those are, and what the weather has been like there over the last few months.  Drought stress might do this, but so might overwatering/flooding and poor drainage.  Or it might be salt on a road nearby the previous winter.  Or bark beetles or borers.  I would definitely say take down the one on the right that looks the worst, and check for borers or beetles in the bark when you cut it up.