It was very expensive, but IMHO still the right choice. What were they supposed to do? The east is still weak (except maybe Berlin), mainly due to a lack of big corporations, chased away into the western parts by the soviets. At least the gap is not widening, but its also not really closing either. It will take many decades.

Luckily we have some federalism to counteract some of Big Country malaise (unlike FR or UK).

In an article in the new statesman recently they talked about western hesitation to unification, both for cost reasons and due to Western resentment against Prussia et al. https://www.newstatesman.com/world/europe/2017/09/what-brita...

It was a mistake not just for Germany, but for Europe in general. Frankly, the unification of Germany in 1871 was a mistake. Prussia, Prussianism, and its antecedent Teutonic Order are some of the worst things inflicted on that part of Europe, including Germany.

Given the military realities of that time, I‘d say it was both smart and inevitable. But definitely disastrous.