I had a few questions about the meaning of "sich etwas (dative) anschließen". It seems that there is many similar, but distinct meanings of this word that I'm struggling to get a good feeling for. Let me give some examples:
Ich sehe eine Gruppe Freunde. Ich werde sie fragen, ob ich mich ihnen anschließen darf.
I see a group of friends. I will ask them if I am allowed to join.
Der Mann schloß sich der politischen Partei an.
Der man schließt sich der Ideologie der Partei an.
Ich schließe mich dir an.
(I agree with you?)
Now, example 1 would suggest that "sich anschließen" simply means "join". This is consistent with example 2. However, "join" does not work anymore for examples 3 and 4, and hence I suspect that this does not simply mean "to join".
Is there a fundamental difference in the use of the word when we are talking about organizations and ideas? Or is there actually some common theme between the uses in 1,2, and 3,4?