problems. >> reporter: aaron david miller advised six u.s. secretaries of state on the middle east. he doesn't think the regime of egyptian president hosni mubarak will fall soon, but miller and other analysts point out, egypt is a crucial u.s. ally. it's the largest and the most powerful arab country, and unlike tunisia, instability in egypt directly impacts the national security of the u.s. and its other allies. >> instabilities of egypt could caught problems on the border of israel. right? >> no doubt. because in the event the egyptians are pre-occupied by issues, internal issues, hamas could break the blockade once again and bring missiles in from iran that could actually target israel again. >> reporter: mark ginsburg is a former u.s. ambassador to morocco. like miller, he worries about the rise to power in nearby lebanon of a leader backed by hezbollah, which the u.s. considers a terrorist group. these analysts say egypt's military likely wouldn't let radical islamic groups there, like the muslim brotherhood,