what alerted terrorists? maybe gunfire and bomb explosions? Tzahal was going thru that whole area.
Despite all the passions, the fact is that holding the border is an important issue. Ask yourself – why it may be a “red line” for Hamas? Obviously, because they intend to use the border for re-supply. So, even if you don’t have detailed information Israeli government has, you can conclude that this is an important issue. I am not telling you what the right solution is in the difficult situation, but at minimum this is not some personal preference by Bibi, but a serious security consideration that one needs to consider. Making the issue into a political pressure point against Israeli government is exactly what Hamas and other sonei Yisroel want to happen.