The conventions that have long governed relations between Arab states have changed. What Arab leaders do within their own countries is now open to criticism, and action.
Domestic policy is the new measure of Arab authority
What did Hosni Mubarak do wrong? Or rather, what did Hosni Mubarak do differently in January of this year that he hadn't done in the previous three decades of his rule, that justified his overthrow?
The answer is not much.
There were lots of things that the former Egyptian president had done that did not chime with the people he ruled: the economy was stagnant, he was too close to the United States, his police and security apparatus was uncontrolled, corruption was rampant. There was a lot of kindling ready to burn, but no spark until Tunisia's revolution.
And yet Mubarak never had a "Bouazizi moment", a badly-judged political reaction to an outlier event. He may have done many things badly in January but he did not do things differently.
Rather, what changed was that after President Ben Ali fled Tunisia, Mubarak's ability to continue to rule Egypt was suddenly in doubt. It was, seemingly, a tiny shift, a small change in the perception of millions of people, not only a feeling that they could take on the security apparatus and win, but a feeling that Mubarak had lost his authority.
It was a small change, but a seismic shift.
A similarly small change with enormous repercussions has occurred over the past few days with the suspension of Syria by the Arab League. The conventions that have long governed relations between Arab states have changed. The idea that what Arab leaders do within their own countries is immune from criticism by the regional body has been overturned.
Back in March, the Arab League, for the first time in its history, sanctioned an Arab leader for how he acted internally, against his own people. By taking steps against Muammar Qaddafi in Libya, the Arab League provided diplomatic cover for the United States and Nato to intervene, a vital step without which there would almost certainly have been no outside intervention in Libya's revolution.
Yet it could be argued that the Arab League acted only when it was pushed. With Syria, there is no similar inevitability; there are still ways for Bashar Al Assad to remain in power. This time, the Arab League has not been pushed to this decision, but have stepped up to it.
Authority is a complicated idea, both between states and within them. In democracies, authority tends to come from the functioning of the institutions that surround power - elections, political parties and so on - and a sufficiently strong mandate from the electorate. That applies in regional democracies, like Turkey and even Iran, and in those that have had imperfect elections, such as Yemen.
In states like Syria, the authority of the leader also rests on a mix of consensus and coercion. In Syria, in the past, there was more coercion than consensus; President Al Assad has tried to change that balance, unsuccessfully.
What the Arab Spring has changed is the idea that leaders can lose their authority to rule because of internal violence. That is a crucial and vital development, created through the people power that has swept the region.
To see what a change this is, think of how some leaders have acted against their own people in the past. In Iraq, Saddam Hussein gassed his own people. In Syria, Hafez Al Assad destroyed almost an entire city. In neither case did regional leaders express that those actions removed the authority of those leaders to rule.
When the Arab League did take action against one of its members - expelling Egypt in 1979 for offering peace to Israel while the occupation continued - they did so because of a stance Egypt took in foreign relations, not internally.
Now look at this year. The Arab League condemned Libya for attacks on civilians and Syria for state crimes. The GCC, too, condemned Yemen for violence against civilians.
If the Arab League sanctions Syria it may go on, for the exact same reasons, to sanction Yemen's government. In any case, a change in the conversation will have occurred. It will suggest, somehow, that there is political flesh that can be placed on the philosophical bones of authority.
That may mean a lot. If the leaders of Libya and Syria can lose political authority for killing their citizens then the costs of such policy choices rise: Syria was expecting a muted response from the Arab League. That it received such a strong condemnation - with an implicit threat to take the issue to the United Nations - means that the days of Arab leaders acting with impunity against their civilians is rapidly reaching its end.
This new philosophy will be positive for Arab leaders. It will help them speak more clearly about regional disputes. Having sanctioned Syria and Libya for attacking civilians in their care, the League can more credibly speak about Iran and Israel doing the same.
But this new philosophy may also contain undreamt-of consequences for the region.
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