The Palestinians are "protected persons" under int'l humanitarian law, while the "settlers" ARE NOT. In addition, those same laws insist that those colonists should not be there at all, since the colonization of occupied territory is unconditionally prohibited. The IDF has a duty to protect them, yes, but the only LEGAL way of doing that is to abandon this colonial enterprise and return all those colonists back inside Israel.
Islamic State militants blow up ancient Arch of Triumph in Palmyra (Reuters)
from the article: Amira Hass, settlers and Palestinians: 'Do we not bleed?'