MAY ONE COUNTRY CROSS ANOTHER'S BORDERS TO ATTACK MILITANTS?

What do you think?  Is it in accord with the laws of nations for one country (the United States) to send unmanned aircraft across the borders of another (Pakistan) and attack militants and jihadists?  And can the U.S. do this without the permission of the second country, Pakistan?

Suppose it were in the opposite direction?  Suppose it were Pakistan that was sending armed drones into U.S. airspace?

The second question takes no little reflection. Most Americans would see it as a violation of national sovereignty and an illegal incursion.  It probably would precipitate an immediate counter-strike.

So why does Obama and Panetta think that they are justified in sending drones into Pakistan?  Is there any clearer violation of international laws?  I don't think so.