That is a complex question and its importance lies with two specific factorsFrom a purely military perspective I am wondering what is the big deal surrounding Donetsk airport? Why does it seem to be constantly under contention?
With all the artillery barrages being traded why doesn't one side or the other just flatten the place while the other side is there? And if it is already flattened why does either side care to "control" it, or maybe occupy would be a more accurate description?
1) It is a very big piece of land
2) It is the front line of the conflict West of Donetsk
The two factors are not unconnected. They are also very different from the factors at Lugansk Airport. Donetsk Airport is a large modern International Airport, while Lugansk was a much smaller city/regional airport. Lugansk was also completely encircled and unlike Donetsk had no direct contact with the main body of Kiev controlled territory.
What this means is that Donetsk Airport sits as a large block to the West of the City. The Eastern End and buildings are controlled by Novorossiya and resupplied directly from Novo held territory, while the main terminal in the West is held by Kiev and supplied by the towns and villages west of the airport which are under pro Kiev control.
Between the two ends is a very long and wide stretch of open ground, overlooked from all sides and totally lacking in cover. It is a classic WW1 no man's land and attempts to cross it as futile and costly as a WW1 offensive.
This is then the key problem as; being a large open space that occupies a large portion of the Western end of the city, it has caused a break in the ability of the Novorossiyans to push their low intensity advance. It is not an urban landscape, with roads and buildings to move through, nor is the countryside with deep cut lanes, woodland and hedgerows to move along and no isolated checkpoints to attack and capture. It is completely open and exposed.
Why does it matter? Well, think about any International Airports you know. In addition to being a major block to movement along a considerable arc of the front, it also is going to be a hub for major roads and rail for the West of the City. Not only will these communications serve the airport directly, they will also force all major routes around the circumference of the Airport. If you do not control the site of the Airport, you do not control these routes and your ability to infiltrate West is frustrated at all levels. The biggest element of control is the high building on the site which will allow for local dominance and very effective artillery spotting.
There is no obvious low intensity answer from the Novorossiyan perspective. The only way to resolve the problem would a massive offensive that swept along the pro Kiev front from both the South and North and which encircled the Airport and allowed the main terminal to be attacked from the West.
To that effectively you need not only a lot of men, but also some rather specialist artillery and munitions, the sort that only a major military like the Russian Federations Armed Forces would possess.
It is one reason why I have to admit that the current stories being reported
are at least credible, even if still completely unsubstantiated by any form of evidence.
I also think that for once, the story is being called accurately.
You can add to Donetsk Airport the city of Debaltseve where another vital highways interchange is held by Kiev to the prejudice of Novorossiyan forces.This was confirmed by US Gen Breedlove on Wednesday, who said "Russian tanks, Russian artillery, Russian air defence systems and Russian combat troops" had been sighted.
Gen Breedlove, talking to reporters on a visit to Bulgaria, said the alleged Russian troop deployment may be intended to reinforce "pockets" under separatist control in eastern Ukraine.
This could, he said, help them to form "a more contiguous, more whole and capable pocket of land in order to then hold on to it long term".
I hope my answer is clear.