Editor’s Note: An earlier version of this story incorrectly stated Russia was landlocked except in the north (it also has an eastern seaboard). We also reported that Russia has two warm water naval bases; there are at least five. The top of the line Russian aircraft seen in Syria are Flanker jets, not Fencers, as we initially reported. Changes have been made in the text to correct these inaccuracies.

CNN  — 

The war in Syria just got a little bit more complicated.

As if the airspace over the war-torn country wasn’t already crowded enough, fighter jets announced Russia’s arrival on the ever-growing list of nations who have bombed Syria when it launched airstrikes on rebel targets in late September.

A coalition of countries led by the U.S. has been bombing ISIS targets on a near-daily basis since last September, in the hopes of rooting out the terror group from its strongholds in Syria.

But Russia’s arrival on the scene marks a new and uncertain chapter in a war that has now killed more than 250,000 people since 2011.

Here’s everything you need to know about Russia’s military intervention in six graphics.

Russia has set up shop in western Syria

For weeks Russian President Vladimir Putin prepared for airstrikes by flying equipment and personnel to locations around Syria – particularly on the Mediterranean coast – including the airport in Latakia, Russia’s naval base at Tartus, and the capital Damascus.

Russia now has seven positions set up in Syria, according to the Institute for the Study of War, a Washington-based think tank.

Russia says it’s taking the fight to ISIS but the U.S. isn’t buying it

The Russians say they will take the fight to ISIS and “other extremist groups” in Syria – but many of the targets they have hit appear to be hours away from the nearest ISIS strongholds.

In early October a coalition made up of the United States, Britain, Turkey, France, Germany, Qatar and Saudi Arabia accused Russia of attacking the Syrian opposition and civilians, instead of fighting ISIS.

Russia’s intervention isn’t just about ISIS

Putin’s intervention isn’t just about bombing extremist groups. Russia has commercial and military interests in Syria it could lose if there’s a regime change, so it is trying to preserve the rule of Syrian President Bashar al-Assad, a key ally in the region.

Experts say Russia is also fortifying its long-established naval base at Tartus, which provides strategic access to the Mediterranean.

And Putin’s deployment of fighter jets around Syria could also allow Russia to extend its military influence across the region – from Turkey (which Russian jets could reach within minutes) and Iraq to Jordan and Israel.

The big guns have raised some eyebrows

Satellite photos taken over the past few weeks show top-of-the range Su-30 “Flanker” fighter jets and T-90 tanks, transport and attack helicopters, and armored vehicles appearing at Syrian bases. According to IHS Jane’s Intelligence Review, the photos show nearly 30 combat aircraft.

The influx of advanced aircraft has raised eyebrows and prompted some observers to question exactly who Russia’s planning to fight in Syria.

“Many of [the weapons] don’t seem to be well-suited to fighting ISIS. They’re built to battle adversaries like the United States,” the Daily Beast reported.

Secretary of State John Kerry was similarly alarmed two weeks ago. He told CNN: “Clearly, the presence of aircraft with air-to-air combat capacity as well as … surface-to-air missiles raises serious questions.”

Meanwhile, the U.S. is suspending its faltering rebel-training program

The U.S. has announced it is suspending its program to train moderate Syrian rebels. The Pentagon plan called for between 3,000 and 5,000 fighters to be trained a year, but so far the U.S. has trained an estimated 75 rebels – some of whom were kidnapped as soon as they crossed into Syria.

This follows on the news that 28,000 foreigners from 100 countries are now fighting with ISIS in Syria and Iraq, according to the U.S. That’s nearly double the figure from 2014.

More than 250 Americans are now fighting with ISIS – more than half of whom left the U.S. in the past year.

Progress in the war on ISIS is being made – at least in terms of land

Despite the year-old U.S.-backed aerial campaign, ISIS hasn’t been beaten back from its key strongholds of Raqqa in Syria, or Mosul in Iraq – and since then the group has also seized Palmyra and Ramadi.

But it appears progress is being made. According to IHS Jane’s Intelligence Group, the territory controlled by the terror group has shrunk by 9.4% in the first six months of 2015.

CNN’s Tim Lister, Beth Brettingham, and Aaron Darveniza contributed to this report.