Back in the days of the Soviet Union, a mere cold usually meant a fatal illness when leaders suddenly dropped out of sight. Ukraine president Viktor Yanukovich certainly picked an odd time to call in sick, as opposition protests mount and activists refuse to accept half-measures meant to allow him a share in the country’s leadership:

Ukraine’s embattled president Viktor Yanukovych decided to go on sick leave Thursday as the country’s political crisis continued without signs of resolution.

A statement on the presidential website Thursday said Yanukovych was on sick leave due to an acute respiratory illness and high fever. There was no indication of how long he might be on leave or whether he would be able to do any work.

Yanukovych is under pressure after two months of major protests seeking his resignation, early elections and other demands.

In one of a series of moves aimed at resolving the crisis, Ukraine’s parliament on Wednesday passed a measure offering amnesty to those arrested during the protests, but only if demonstrators vacate most of the buildings they occupy.

The move was quickly greeted with contempt by the opposition, as were the previous efforts to calm the unrest.

Essentially, the offer from the parliament — still controlled by Yanukovich’s party — was “trust us.” The time for those kinds of back-down-now-and-we’ll-think-about-changes offers appears past. Having gained the leverage of holding ground, especially after their previous experience with Ukrainian security forces, there won’t be any way to coax them into ceding that ground without rock-solid assurances that they have changed the political situation for good. The only way to ensure that now is to see Yanukovich resign.

That brings us to the curious case of the sick leave. Certainly people get sick occasionally, and people under pressure are more likely to get ill. The government insists that’s the case here:

“Today is the first day of the illness. He has a high temperature. We are not doctors, but it is clear that a high temperature does not go down in a single day,” a presidential spokesman said by telephone. “The doctors will do all they can so that he can recover quickly.”

Some opposition figures said they suspected Yanukovich might be giving himself a breathing space after being forced into concessions to try to calm the unrest on the streets.

“This smacks of a ‘diplomatic illness’,” Rostislav Pavlenko, a member of boxer-turned-politician Vitaly Klitschko’s Udar (Punch) party, told Reuters. “It allows Yanukovich not to sign laws, not to meet the opposition, absent himself from decisions to solve the political crisis.”

Pointedly, Yanukovich still has not signed the legislation that repealed the ban on public protests, a law passed this month which threw a deluge of gasoline on an already-raging political fire. Being absent means not having to do one’s homework, the opposition alleges, including allowing for the police to operate under the old law.

However, the declared “sick leave” comes at the worst possible time for Yanukovich and his supporters, especially with the Soviet precedents fresher in their minds than in Western minds. Even if he is that sick, it’s going to sound like Yanukovich is wobbly, which will only raise morale amongst protesters and have Yanukovich supporters looking for ways out of the crisis that don’t include being up against the wall. Under these conditions, even the appearance of a vacuum of leadership at the top can be fatal — literally and figuratively — and the benefit of delaying signatures on concessions already offered and accepted is weak at best. Yanukovich had better get well in a hurry if he expects to survive this crisis.

Update: By the way, the split in Ukraine is not as simple as just a geographic split, either, although it’s tempting to just stick to an “East=Russophile, West=Europhile” look at Ukraine. It’s a complex divide that has echoes in history, culture, ideology, and so on. As the BBC noted earlier this week, there is unrest in the East, too:

This cold, grey place is in Ukraine’s industrial heartland: it is a city of giant enterprises, heavy industry and blue collar workers. Like many regions in eastern Ukraine, Zaporizhya is traditionally loyal to President Yanukovych, who is from the east himself. That makes what happened here at the weekend so unusual.

On Sunday, thousands of protesters gathered outside the regional administration building to demand political change. They condemned the president and called on the local governor, appointed by the president, to resign.

The defiant governor, Alexander Peklushenko, emerged to announce that only “cowards and traitors” resign. He vowed to retain his Party of Regions membership card “until the day I die”. Then he disappeared back inside.

The angry crowd tried to push past the lines of riot police and into the building. The police fired tear gas and stun grenades. …

It appears that Viktor Yanukovych still enjoys support in eastern Ukraine and there are some here who believe he should rule out concessions to his opponents. But the fact that unrest has spread here, and to nearby cities like Dnipropetrovsk, which are normally viewed as a central part of his powerbase, will be of major concern to the embattled president.

The flashpoint in this unrest was definitely the reversal on the trade agreement with the EU, but that’s not all that’s going on in Ukraine, either. For instance, corruption plays a part in the outrage over the current government, or at least the perception of corruption:

Further along Khreshchatyk Street, another protester, Genadi Chemov, is standing between a high-end hotel – still open for business – and a ten-foot barricade made of snow, ice, and other debris chiseled off Kiev’s brick streets. Mr. Chemov, like Moroz, was unimpressed by Tuesday’s special parliamentary session.

Chemov, a Kiev resident, says he is fed up with the endemic government corruption and usually comes to the protests once a day and sometimes stays for up to six hours before going home.

As he warms his hands by a wood fire, Chemov explains that Mr. Azarov’s resignation is just symbolic. “It’s the president who needs to be held accountable.” Until Yanukovych leaves power, there’s no way that the Euromaidan protests will go home, he says.

Be wary of single-issue analyses on this topic. In a functional republic, a trade agreement decision would hardly be the flashpoint of a potential civil war. The political fragility here goes back years, if not decades.