Mikheil Saakashvili has never been shy about picking fights.
As president of Georgia, he fought his country's notorious corruption, but using an authoritarian style of governance that has left him wanted on criminal charges in his homeland.
He also sparked a war with Russia in 2008 by attempting a military takeover of the Moscow-protected breakaway territory of South Ossetia.
And when he came to Ukraine earlier this year to serve as governor of the corruption-infested Black Sea port of Odessa, he squared off publicly with the region's most powerful oligarch, Igor Kolomoisky.
But last week, Mr. Saakashvili picked a fight with an opponent that no one expected – Arseniy Yatsenyuk, Ukraine's prime minister – with an apparent eye towards replacing him.
Saakashvili, a staunch supporter of Ukraine's Maidan Revolution, was one of several foreigners brought in to help Ukrainian President Petro Poroshenko's reform the war-torn and corruption-ridden country earlier this year. In May he was given the job of governing Odessa region, a hotbed of organized crime and pro-Russian sentiment.
A Ukrainian-speaker who studied in Kiev as a young man, Saakashvili has made waves by firing the head of Odessa's port authority, slashing bureaucracy, and sparring with Mr. Kolomoisky. Most experts say the jury is still out on the effectiveness of the former Georgian leader's barely three-month-old tenure in Odessa.
But last week on the Channel Five TV station, which is owned by President Poroshenko, Saakashvili launched a withering verbal assault of Mr. Yatsenyuk, accusing him of undermining reforms, protecting corrupt officials, and siding with oligarchs like Kolomoisky.
"We’re talking about sabotage by central government," Saakashvili said, directly fingering the cabinet headed by Yatsenyuk. "Now the government is paralyzed. There must be a total reset of the Ukrainian government on all levels."
Within days a petition appeared on the president's official website asking Poroshenko to fire Yatsenyuk and appoint Saakashvili in his place. It now has thousands more signatures than the 25,000 that would require the president to officially consider the issue.
A mixed record
Controversy is not new to Saakashvili. His sweeping reforms as Georgian president are widely agreed to have curbed Georgia's notorious corruption, but also attracted widespread criticism for alleged human rights violations.
He left Georgia two years ago after his party was defeated in parliamentary elections, and last year Georgia's top prosecutor filed charges against him for "abuse of power" – charges he insists are politically motivated.
As governor of Odessa, he has pledged to quickly make the region into a beacon of progress to inspire all Ukrainians. That hasn't yet happened, and his complaints of "sabotage" suggest he may have run into serious headwinds in what is one of Ukraine's most politically complex places.
"Saakashvili has delivered no successes in Odessa. He's a master of PR, and he's certainly raised the expectations of the local people," says Vadim Karasyov, director of the Institute of Global Strategies in Kiev. "But as for actual results that would give him genuine political weight, there are none so far."
Opportunism ... but whose?
Ukrainian experts are divided on whether Saakashvili is really making a bid for higher office, or is simply being used by Poroshenko as attack dog against the president's main rival, Yatsenyuk.
"I think this is all Saakashvili's initiative," says Ruslan Bortnik, director of the independent Institute of Analysis and International Politics in Kiev. "He made it clear he didn't want to get stuck in Odessa. He sees that Ukrainian political forces are rapidly realigning, Yatsenyuk's approval rating has practically dropped off the radar screen, "and he thinks it's a good moment to aim for a higher position." he says.
Mr. Karasyov argues that Poroshenko is using Saakashvili as a "battering ram" to cow Yatsenyuk, but not to drive him from office.
"The ploy is to tie Yatsenyuk more closely to the president. If he was fired, his party might leave the president's parliamentary coalition, and that would be quite destabilizing. This idea of bringing in foreigners to do things is not a viable solution for our problems. Ukrainians play by different rules."
Yatsenyuk's party, running at barely 3 percent in the polls, has declined to take part in next months regional elections, and declared it will back Poroshenko's bloc in the voting. In a scathing article for Ukrainskaya Pravda this week, Saakashvili argued that "when the prime minister's party refuses to take part in elections, it can only lead to the de-legitimization of power."
Amid growing turmoil in Kiev and a widespread hunger for fresh leadership, Saakashvili may sense political opportunity. A comprehensive poll on Ukrainian public opinion, conducted by the International Republican Institute in July, found that 72 percent of Ukrainians think the country is going "in the wrong direction" and only 3 percent are "satisfied with the pace of [positive] change." Less than a third are willing to endure more economic pain in hopes of a better tomorrow, and nearly two-thirds have an "unfavorable" view of Poroshenko. Nearly 85 percent disapproved of Yatsenyuk.
"Saakashvili was clearly given a green light to attack Yatsenyuk. Whatever else happens, I don't seem many prospects for Yatsenyuk and his party in the next five years," says Mr. Bortnik.