Syrian analysts in Damascus argue that if no candidate is found, the resultant power vacuum will plunge the country into a bloody renewal of its 13-year-old civil war.
"He was able to play a moderating role and create dialogue between Kurds and Arabs," said Ammar Abdelhamid, a Syrian political analyst.
Syrian analysts expect the government to hand over any low-level figures indicted in the investigation.
And since Iraq's defeat, many of the Syrian public's concerns about the country's stance have abated, Syrian analysts and diplomats here said.
"I think that this is the most important challenge facing Syria in its recent history," said Fayez Sara, a Syrian political analyst and writer.
Those means, according to most Syrian analysts, include Iran's military as well.
He is considered one of the most powerful men in Syria and according to Syrian analysts no foreign company can do business in Syria without his consent and partnership.
The Syrians generally dismissed the Lebanese as ungrateful, said Sami Moubayed, a Syrian political analyst.
"Asef Shawkat is a very strong man, and it's not just about the love story between him and Bushra," said a well-connected Syrian political analyst, who asked not to be identified for fear of arrest.
In effect, Syrian analysts say, he must devise a split between the party and the government, cutting the party's decades-old cronyism and control over the government.