Two years on from being annexed from the rest of Ukraine by Russian forces, tensions between Moscow and Kyiv over Crimea are rising again.
The latest round of worries have been sparked by accusations of Ukrainian incursions into the Crimean peninsula.
Russia's foreign ministry said that the alleged death of servicemen last weekend during clashes would have consequences, Reuters reported, though Ukraine has denied that the skirmishes took place.
The latest row has prompted analysts to take a fresh look at the problems surrounding Crimea and why relations are under strain again.
Using a fresh piece of analysis from Timothy Ash, head of emerging-market strategy at Nomura International, CNBC take a look at six reasons:
Duma elections
Russia's lower house or State Duma elections are due in just over a month's time on September 18. President Vladimir Putin is keen to impress voters in an effort to bolster support for the United Russia party, which is currently hovering around 60 percent.
"Putin never likes to take chances with domestic politics, and will want to impress on the Russian electorate his own strength, and how lucky they are to be Russians citizens, as perhaps compared to their Ukrainian counterparts," Ash writes.
A big win for United Russia will likely be seen as a reflection of popular support for Putin, he adds, especially with the presidential ballot set for March 2018.
Russia needs distraction
Moscow's involvement in Syria has failed to deliver a victory, Ash points out. A rising death toll and recent deadly strike on a Russian helicopter have softened public support for the military intervention.
There are fears that attention could slip back to domestic politics, Ash explained, providing some "logic for intervention in Ukraine."
Daragh McDowell, a principal analyst for Europe and Central Asia at Verisk Maplecroft, agrees that Russia's actions in and around Crimea are "more about domestic politics than anything else," calling it a continuation of the "demonstrative strong-man security state," characteristic of Putin's regime.
"Anything that can enforce a mentality of 'Russia against the world'...all serves the same basic message that it's big hostile world out there, everyone's against Russia, and I'm (Putin) the only one that can protect you," McDowell told CNBC in a phone interview.
Ukraine’s independence day
Renewed conflict in Crimea and the Ukrainian region of Donbas could also help divert attention from the 25th anniversary of Ukrainian independence from the Soviet Union, which Ash says will be celebrated with much "fanfare" in Ukraine but "expose scars and vulnerabilities in Moscow" ahead of the State Duma elections.
"How better to provide a distraction therein than through a re-escalation on the ground in Crimea/Donbas, allowing Russians and Ukrainians to question what has been gained from independence by Ukraine," Ash explains.
However, McDowell says that if this is an impetus towards Kremlin foreign policy, it's a mistaken one.
"It could very well be that they think it would be good idea to rain on Ukraine's independence day parade, but in reality we would expect such a move to backfire spectacularly," he said.
Domestic changes in Ukraine
While international observers see promise in Ukraine's anti-corruption drive, Moscow is worried that details over the alleged Russian intervention in Ukraine could come to light during high-profile arrests of individuals with ties to former president Viktor Yanukovych.
"So perhaps this latest re-escalation is a warning to the Poroshenko administration not to cross red lines," Ash writes.
It is also noted that the Ukrainian economy is starting to recover, with gross domestic product growth set to rise around 1 percent, while Russia's real economy is set for a GDP contraction of 0.5 percent.
"In the past, military re-escalation in the East has worked to destabilize the macro economy in Ukraine...There may thus be a desire to go back to past proven policies and to try and weaken the comparative Ukrainian economic performance," Ash explains.
Trump’s slowing momentum
With the likelihood that Republican candidate Donald Trump will be elected as president dwindling, Putin is looking for an opportunity to strike deals with the west with either an outgoing President Barack Obama or a possible President Clinton.
"With this in mind, and with an eye on a hawkish Clinton presidency, perhaps there is a desire now to try and cut a deal with the dovish Obama administration, just before it exits."
However, McDowell said he'd be skeptical that Russia is evaluating its policy options this way, and the idea of Trump being the 'Siberian' candidate — suggesting he would likely follow pro-Putin foreign policy at America's expense — has been overblown.
While a Trump victory may be seen as great for chaos in the U.S., Putin doesn't see that much difference in the way Obama and Clinton operate, McDowell said.
"We do know that Putin is believed to have a very strong personal dislike of Hilary Clinton, and does not get along with her at all, but this doesn't necessarily mean that he would regard Obama as more pliable and doveish than Clinton."
Upcoming G-20 talks
In an attempt to legitimize its control of annexed Crimea, Putin is likely to ask for a joint declaration against terror attacks at the upcoming G20 talks in China, Ash notes.
The main reason behind the move is that the Kremlin has characterized the alleged Ukrainian incursions in Crimea as terror acts.
However, it's likely to be blocked by western powers at the G-20 table.
"Putting all the above together perhaps the on-going rise in tensions, and risks of re-escalation, is some kind of effort by Putin to secure a one-on-one with President Obama at the G20, as one of his (Obama) last acts in power, and an effort to "deal" over Ukraine and Crimea," Ash explains.
It wouldn't make much sense for Obama to "play ball" with Putin so close to his political handover, but it's unlikely to stop Putin from trying, McDowell stated.
The G-20 summit is set for September 4-5.