The how only matters to questions of legality, not questions of morality.
Yes, or no - should airplanes in flight be forced down so that third-party countries can make political arrests? The EU seems to think that the answer to that question is 'Yes'... As long as it's done by it, not to it.
If in the middle of the flight, you are told that you were surprise - banned from flying over multiple countries in your flight plan, you are forced to abort your flight and land, unless you want the plane to run out of fuel and crash in the middle of nowhere.
And again - this is a pointless semantics game. Yes or no - is messing with airplanes, in flight, in order to make political arrests acceptable behaviour? You seem to think so (As long as its done in some particular way.)
The only difference is that one of the two planes had more options for where it could land. Both had to land at somewhere other than their destination, though, unless the pilots wanted everyone on board to die.
I don't give a rat's ass if France, Spain, Portugal, and Italy can deny an in-flight commercial airplane access to their airspace to make a political arrest. They clearly can, and did. I am asking you if they should do that. Does that seem right to you?
I think GP has done a fabulous job explaining why this isn't true, so your continued assertions that it is are strange.
Perhaps there are differences between these two circumstances after all?
It was indirectly forced, if the other options were to either be shot down by entering unauthorized airspace or to land.
If it could have returned safely it probably would, but fuel is a very limited resource in a flying plane.
Finally, consider the motivations of its owner - Evo Morales. While I have no objection to his political aims; it is nevertheless wise to consider that he does have political aims. And as it so happens, he's a populist, anti-imperialist, anti-US political leader. For him, seeking this confrontation would have been a pure win; and furthermore being seen as the victim of imperialist oppression would have been the cherry on top. As such, it's just not reasonable to assume that his actions were aimed to defuse the situation; if he could appear to be victimized by imperialist forces, that's to his benefit.
So it's entirely plausible for him to choose to land in Vienna instead of return. It's not very plausible fuel was running low. Additionally, there are about a dozen other countries very close by he could like have chosen to land in, even if fuel was scarce - he wasn't in some inescapable box.
