I told you. The Germans started importing gas from the Soviet Union when Willy Brandt was Chancellor.
As for why they increased the footprint of natural gas in the economy you can thank the Green Party in Germany for forcing the nuclear phaseout. Schroeder cut a deal with the Greens in order to get a ruling majority in Germany. And the only reasonably inexpensive alternative the Greens would accept was renewables with natural gas for peaking. Coal is too expensive because of carbon taxes also due to Green agenda.
West Germany bordered the Warsaw Pact. Modern Germany borders NATO countries. So this was to be expected.
It is Poland and Romania who will have to take the brunt of the defense burden.
As for the lack of investment into the German armed forces, there were cuts in government investment all around. Germany had this holier than thou attitude after the 2007-2008 Global Financial Crisis where they decided austerity was the solution to all ills. And that is also when caps to government deficits where put into place.
Because of that the trains and the military in Germany are dysfunctional. Germany has an obsolete network infrastructure with most of the country still on DSL.
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