President Ali Abdullah Saleh's apparent readiness to deal more violently with protests against his 32-year rule could drive Yemen into a Libyan-type conflict.
Popular revolts in Egypt and Tunisia inspired more unrest in Yemen, an impoverished country already seething with rebellions in the north and south and widespread discontent after decades of economic hardship, corruption and misrule.
One person was killed and scores were hurt yesterday when police fired bullets and tear gas at protesters in Sana'a. Five people died in anti-Saleh rallies across Yemen the day before.
Sarah Phillips, at Sydney University, said the bloodshed showed Mr Saleh had few cards left other than to hit out hard.
"I doubt that anyone will be moved by his offers of dialogue as they have been offered insincerely on so many previous occasions and it is plainly an act of desperation."
Demonstrators, mistrusting Mr Saleh and unconvinced by Washington's calls for dialogue, insist that he step down at once.
The Yemeni political analyst Abdul-Ghani al Iryani said: "Too many years of back-room deals between the regime and the opposition coalition have left the protesters with no faith in either. All they want is for the regime to fall.
"They are not open to any dialogue, as it may be hijacked by the same suspect political elite.
Mr Saleh has made many verbal concessions, promising to step down in 2013 without bequeathing power to his son and offering a new constitution giving more powers to parliament, as well as announcing an array of handouts the treasury can ill afford.
Even so, he has rejected opposition plans for a phased transition of power this year, even as he haemorrhages support from previously allied tribes, Islamist clerics and politicians.
A rift between Mr Saleh's Sanhan clansmen, who dominate top military and security posts, and sons of his powerful former ally the late Sheikh Abdullah al Ahmar threatens to turn the political struggle into a tribal feud.
The International Crisis Group said last week: "The spectre of descent into tribal warfare makes many Yemenis nervous. The rules of the game are in flux, presenting an uncommon opportunity for serious reform, but also for violent conflict."
The US, which along with Yemen's main financial backer Saudi Arabia, has long seen Mr Saleh as a bulwark against a dynamic al Qa'eda network, has called for dialogue on a "peaceful transition".
But Mr al Iryani said US and European backing for Mr Saleh's latest offers indicated "misplaced good faith in regime intentions" and had backfired, perhaps encouraging the president to crack down on protesters.
Mr Saleh, 68, has not subjected Yemen to the same brutality of the former police states in Egypt and Tunisia, preferring to co-opt his foes, allowing some space for dissent and to dish out money and favours to important tribes and the military-security elite.
Yet if Mr Saleh feels cornered, he may decide to apply more force, a move that Mr al Iryani believes would trigger sanctions such as those imposed on Libya.
Phillips said at least one prominent member of Mr Saleh's Sanhan elite had declared support for the demonstrators, threatening the solidarity of his inner circle.
"With that cohesion visibly cracking, it is difficult to see how his leadership could survive for very much longer, at least without massive external support and considerable brutality."
Mr Saleh also plays on what the ICG report called "a large wellspring of negative legitimacy, given the absence of a clear or popular alternative leader".
But his government has failed to meet the basic needs of Yemen's 23 million people. Oil wealth is dwindling. Water is running out. More than two fifths of Yemenis live in poverty.