If one's connection is corrupted when your guard and exit node is the same person (that can then analyze your traffic and based on that figure out your IP), why does Tor allow them to be from the same country?
1 Answer
Same country does not mean same person.
Have a look at the bubble graphs. Germany provides currently the most relays among them there are 645 guard nodes and 138 exit relays. So it quite likely that you select some relays from Germany.
Tor looks for for relationships among relays and don't make connections when it assumes that two relays belong to the same person or network. SO this provides some safeguards against traffic analysis.