There are many news articles today about how the German government is reluctant to allow Leopard 2 tanks to be given to Ukraine. For example, the BBC reports:
Under German law, the government in Berlin would have to give its permission before countries such as Poland or Finland could commit to re-exporting them. [...] Berlin was reported this week to have made a decision on the Leopard conditional on the US agreeing to send Abrams tanks, which it is not intending to do. [...] There are fears of escalation in Berlin and of going it alone.
I've skimmed about a dozen popular news articles now but am still none the wiser as to what the German government thinks would be bad about providing / allowing other countries to provide tanks specifically, or providing tanks despite the US not doing so.
What I've found so far
Some of the attempts at explanation I've found in popular news media so far and why they are unsatisfactory:
Depletion of Germany's own arsenal
This is claimed to be one explanation offered by the German government in a Deutsche Welle article. The article quotes a defense expert who says this is nonsense, but even if it wasn't, it wouldn't explain why Germany is also blocking other NATO countries like Poland from sending its Leopard 2 tanks to Ukraine.
Not wanting to anger Russia
An article in The Hill claims one motivation behind the US and Germany deadlocking each other on the tank issue is that
[...] then both countries get to avoid sending something they consider provocative to the Kremlin,”
But why would tanks be more provocative than all the other weapon systems sent so far?
Dependence on Russian energy
This is a variant of the point above in that it relies on the idea that tanks would be considered especially provocative by Russia, but it's only implied in one half-sentence of a Reuters article:
Members of the SPD have defended Scholz and warned of being drawn into what could be considered a direct confrontation with Russia. Germany is also heavily dependent on Russian energy.
So the idea is that if Germany specifically draws the ire of Russia, gas supplies could be cut off, at great damage to the German economy and popular support for the current government. As I said, it suffers from the same weakness as the explanation above.
Anything to do with World War II or pacifism
From the Reuters article I already cited above:
Unlike other Western allies, Germany did not supply weapons to Ukraine before Russia's invasion on Feb. 24 and even blocked other nations from sending German-origin military equipment, given a long-standing policy of not exporting arms to war zones. That policy had broad public support given Germany's bloody 20th-century history and resulting pacifism, and specifically guilt towards the Soviet Union over World War Two.
Again the question can be asked why sending other weapons can be considered pacifist and not exacerbating guilt over World War II, but not tanks.
So what is the actual explanation?