It is not a surprise that the US looks after its own - protection of our own sovereign capabilities has always been high on our own countries agenda for years, so its no surprise that the US does it.
However, doing it on such a scale may well have its repercussions which uninvolved parties will come to regret it, as US manufacturers of other systems are frozen out for not being 'European enough'.
Its also likely that there will be no overseas bidders for any large future procurements leaving US bidders to really overcharge the DOD and then the complaints will really start.
Sometimes the hypocrisy is however quite ridiculous. In a recent case, a UK company submitted a White paper to DARPA for an advanced concept and were after the usual intervening period of work, were paid for a definition study. However, when the US DoD decided to move to the next stage they classified the tender as NOFORN i.e. US companies only.
The contract was not awarded, as none of the US companies had the faintest idea how to make it work in practice and unsurprisingly, the UK company told DARPA where to shove it when they were asked to support the US bidders with clarifications.
Revenge is a dish best served cold .