With a stand-off in streets, and negotiations under way, each side needs to hold its people in line and offer enough to make the other side break ranks and go along:
Opposition groups demanding the resignation of President Hosni Mubarak failed to agree a common stance before negotiations with Vice President Omar Suleiman to pull Egypt out of its worst crisis in 30 years.
State television said Suleiman began meetings with prominent independent and mainstream opposition figures on Saturday to go through the options, which center on how to ensure free and fair presidential elections while sticking to the constitution.
The opposition is obviously fragmented and vulnerable to being split apart based on some wanting to get back to work, others being satisfied with what has been achieved so far, and others fearful of chaos breaking out.
The government has to worry about security forces fracturing--especially the army--and for factions in the government to break out of worry and cast their lot in with the protesters to preserve their own position. The government as a whole may worry that having the country shut down economically could hurt Egypt (and ultimately them).
There is another potential problem as each side wages a political war of attrition. Something could happen that sparks open war between the two sides. This could be an accident from simple proximity and tension. Or it could be from actors who don't want a compromise. Somebody in the opposition side would rather see chaos and a bloody revolution, believing that is the best way to power. And somebody in the government or the ruling class would like chaos in the belief that it would provide an excuse to use maximum violence against the protesters.
And even aside from the bloodshed. How do we come out smelling like a rose if the radicals on either side win? Can we persuade Moslem Brotherhood types to be nice to us once they win despite our efforts at getting a compromise? Can we maintain our good relations with the government if it wins with a bloody massacre despite our efforts to ease the Mubaraks and the elites out of power? How would we look to the Arab world if we back such a crackdown despite our ideals of wanting freedom and democracy?
Which is why we need to be involved in getting a compromise between the two sides--and get it done fast. The longer this war of attrition rages, the more chance there is that it could escalate into a crisis that we can't come out of on the winning side.
UPDATE: Another reason (tip to Mad Minerva) we need to have a sense of urgency to settle the differences between the two sides: bread production is halted in Egypt.
UPDATE: Taheri on those sparks that could break the stalemate.