In the Middle East, it has often begun the same way: a popular swell of street protests against long-entrenched autocrats and demonstrators inspired by burgeoning aspirations for democracy and freedom.
But then the military moves in. Its ruthless, harsh force helps prop up the leader and his family, or safeguard the military's own longevity after a leader falls. Death, detention and disappearances become commonplace and in some cases, ruinous civil war with external intervention breaks out.
Organizers of the pro-democracy protests in Sudan say the death toll across the country since the violent dispersal of their sit-in camp in Khartoum earlier this week has increased to 60. Sudan's deadly crackdown has evoked Arab Spring bloodshed from earlier this decade — uprisings in Egypt, Syria and Libya. Tunisia was the one nation to escape mass carnage.
Here's a look at military crackdowns across the Arab world since 2011:
The Arab Spring was born in Tunisia, where it was called the Jasmine Revolution. The country had long been wracked by widespread repression, high unemployment, rocketing inflation and endemic corruption under the rule of President Zine el-Abidine Ben Ali.
The self-immolation by a beaten down and humiliated street vendor Mohammed Bouazizi led to nationwide protests fueled by social media that brought down the longtime authoritarian president in January 2011. He fled into exile to Saudi Arabia.
That ushered in democracy for Tunisia and inspired similar movements around the Arab world. Though there were deaths in the struggle, it was nowhere near the bloody tolls of other Arab nations. The revolution transformed Tunisia into a fledgling democracy that became a catalyst for the Arab Spring, then miraculously transcended it as the only country to keep its transition peaceful.
There were heady days in Cairo's Tahrir Square when the January 25 Revolution took hold in 2011 and within weeks, toppled autocrat and key Western ally President Hosni Mubarak. There were striking scenes as Mubarak loyalists swept into crowds on camels, beating protesters. Calm was restored when the Supreme Council of the Armed Forces took over, and the people cheered the troops. The military was to rule until elections were held in June 2012.
Then, the one-year reign of freely elected President Mohammed Morsi, whose Muslim Brotherhood subsequently engaged in concerted power-grabbing, was brought to a sudden end by the military's removal of Morsi, following mass protests against his divisive rule. Defense Minister Gen. Abdel el-Sissi took over and won subsequent elections deemed fraudulent by detractors and some analysts.
The worst bloodshed occurred in August 2013, when troops under el-Sissi's command descended upon protest camps filled with Morsi's supporters, killing hundreds in Cairo's Rabaa al-Adawiya Square and elsewhere in a single day. Morsi remains in prison facing a life sentence while a death penalty against him was overturned.
Voters in Egypt recently approved constitutional amendments allowing el-Sissi to remain in power until 2030, a move critics fear will cement his authoritarian rule. Opposition and freedom of speech has been largely crushed in Egypt while el-Sissi has been lauded by President Donald Trump for his crackdown on Islamic militants.
The Libyan chapter of the Arab uprisings took a violent turn immediately after demonstrations erupted in several cities over housing in January 2011. Protesters were fired upon and fought back in an armed revolt as the country — held together for four decades by the mercurial cult of personality and wealth cultivated by Moammar Gadhafi — began to unravel. Civil war raged and widespread abuses were committed by both Gadhafi's forces and the rebels.
Western forces intervened on the rebels' side with punishing airstrikes that helped lead to Gadhafi's ouster as he was caught in his native city of Sirte. His killing was captured on video and then seen online around the world in all its gruesome detail. For days, the rebels showed off Gadhafi's body so the nation would believe he was dead.
After Gadhafi's ouster and killing, Libya sank further into chaos and turmoil, with the country divided today between two governments and an array of militias fighting for power and territory.
The uprising in Syria began in March 2011. In the city of Daraa, youths scrawled graffiti against the rule of President Bashar Assad. Having witnessed cataclysmic events in Egypt and Tunisia, Assad's forces moved quickly to brutally crush the opposition.
But it wasn't to be a relatively swift and merciless crackdown as the 1982 Hama massacre by Assad's father, Hafez, which killed thousands. Instead the country lurched into a civil war, now in its ninth year and counting. Hundreds of thousands have been killed and millions more internally displaced or having fled to other countries.
Atrocities committed by the government, including chemical attacks, as well as those by rebel groups and the Islamic State group, which at one time controlled a third of the country before it was vanquished, have been relentless.
The bloodiest chapter in the war may still loom, in rebel-held Idlib, with tens of thousands of civilians in the crossfire as Assad's government, backed by Russian airpower, has pledged to recover the province and every other inch of Syrian territory lost during the war.
Last December, as Sudan grappled with rising prices and shortages, the Sudanese Professionals Association planned a march to the capital, Khartoum, to demand wage increases. When separate demonstrations over rising bread prices erupted in Atbara, a railway hub north of Khartoum, the SPA broadened its demands to the overthrow of the government, invoking slogans from the Arab Spring uprisings.
The umbrella group of unions succeeded in April where war, sanctions and the International Criminal Court, which had indicted President Omar al-Bashir on genocide charges in Darfur, had failed — ending his three-decade rule.
But the military's crackdown this week as security forces overran the main protest sit-in site, followed by its call for snap elections in the coming months and dismissal of protesters demands, appears to show the army has no intention of ushering civilian rule and relinquishing its own power any time soon. The Sudanese generals now say they want to resume negotiations with protest leaders but the demonstrators dismiss such calls as long as troops are shooting and killing them.