It was the tiniest nation there. They had no chance, using logic I would have gone for them first since they were fairly close. So, instead of having probably about 1m soldiers die and then probably civilian casualties of around 15k people die they surrendered. Plus their is also the fact that even if I sent them in logical short bursts of soldiers they would still lose. Even if I didn't want to give up my nation I would prefer surrender over thousand dying (In real life when the people aren't just numbers.), wouldn't you?