Considering Russia annexed Crimea in a matter of days, I don't think that gives Germany enough time to fix their equipment operational.

Their risk analysis therefore probably concludes that the present LIKELIHOOD of an invasion AND a successful occupation is too low to worry about.

That's the difference between the paranoid and the rational.

Then, what's the point of having any military equipment at all to worry about?

Mind you, failing at this gamble would have devastating effects, as was evidenced by many occupied nations during the last major conflict in Europe.

My guess is its to keep enough professional officers and enlisted staff to be able to mobilise and upgrade their capabilities quickly (with or without allies) in the even the risk evaluation changes.

Note that Costa Rica has no defence force at all.

> failing at this gamble

Yes, all adult decisions are based on uncertainty. Especially when resources are limited.

They won't have time to train up the manpower. Even if the US gives them more equipment.

For example, it takes the US Army almost 2 years to train helicopter pilots. Similar for Air Force or Navy pilots.

German troops have very good discipline, and a far more reliable education than american troops. While certainly far from ideal, the state of the Bundeswehr is often painted worse than it is. You completely gloss over the fact that german (special) forces are in a lot of countries.

Furthermore, Germany isn't militarily threatened by any country with capabilities to invade it. France and Britain are close allies, the US kinda still is, Russia's economy is extremely reliant on Germany and the other countries around it are to small to pose a serious threat.