Are you 100% sure it's America who blew up those pipelines? If there is an undeniable truth that Americans blew up those things then yeah that sounds like a very drastic move they did.
Why would Germany worry about any other place other than Germany? Because they are in European Union and in NATO, which means they are not a lone wolf who does whatever they want for their country. This is same mindset MAGA has: "fukk those other countries. what about me"
Germans sending billions of dollars to russia which puts Eastern Europe in danger, which means European Union becoming chaotic than it already is. Which means costing partnership with other countries because they no longer trust you that much.
I don't believe it was America who destroyed the pipeline either, but Germany is a curious case because there are still many existing relationships prior to the Berlin Wall coming down. Not saying Germany had a favorable view of Soviet occupation, but just because the Wall came down doesn't mean all of those business/political ties went away. Its only been 30 some odd years, some folks got rich when it came down in their 20s and 30s and are only in their 60s. Gerhard Schroeder for instance Benefited greatly from his relationships with Russia.
The real problem I see here is America military hegemony was used to form allegiances as a new world order arose, and those allegiances were strengthened because America became Europe's big brother, it allowed Europe to focus on economic development rather than military development, and because there really was only 1 big dog as a military power (its apparent now USSR was only a ballistic and tank power), most wars between major powers ceased.
It really was a genius strategy, but the US got a little power drunk after 9/11 and the cards started to fall.