"And while we are at it, we should also ban US companies from providing critical infrastructure like this in Germany (and Europe). After Snowden, its clear that hardware from US vendors like Cisco should be seen as potentially compromised"
The relationship between the US and Europe for many reasons is different, most specifically, the US will not use 'Cisco spying' to steal German companies IP, or to otherwise screw up Germany.'
In the bigger picture, the US provides the first and last line of defence to Europe. Putin is actively trying to 'pull a Crimea' in the Baltic states and only US led activities are keeping them out. That's the top of the iceberg.
Also the 'Cisco spying' that is done by the US, mostly in the Middle East etc. actually has a lot of security value for Europe.
Of course, Europe is way behind on many tech fronts and would be hurt badly by being cut off by America (you don't think there will be repercussions?) though Europe doesn't need anything made in China ... they need China as a customer for stuff.
There are 100 consumer related issues to be addressed between US/EU before the possibility of Cisco spying comes into question.