http://JewishHistory.org
The Duke of Wellington once said that the only greater problem than defeat is victory. By that he meant that the defeated side knows what it has to do in order to regain itself, while the victorious side is always in doubt what to do with its victory.
The Hasmoneans win the war, now what happens? How do they create an independent state and ward off the Greeks?
What happens is- Simon, who is the surviving Hasmonean brother and ruler of the country, in order to safeguard the country from a new attack by the Greeks, makes an alliance with the Romans. The Romans keep the Greeks out of the country, but they themselves stay in the country.
Simon is a righteous person, he has the support of the Sanhedrin and the people. He is the High Priest, and he is also the ruler. The Rabbis always objected to concentration of power- but because of Simons righteousness, they allowed it temporarily, and he did not abuse the power.
The Rabbis also objected to the fact that the Hasmoneans forcibly converted the Idumeans. The Idumeans did not convert out of conviction, but rather for primarily political reasons. The Rabbis always opposed conversion for alterior motives.
This is based on the Jewish idea that one need not be Jewish in order to have an eternal soul, merit the world to come, etc. Judaism, out of all the monotheistic religions, is the only one which is not exclusive. By contrast, Catholicism inists that the only way one can be saved is through Jesus, and in Islam the only way one comes to the world to come is through belief in Mohammad. Judaism does not have this exclusivity. Therefore, while in other religions they have a drive to force conversion, as they view it as a favor, Judaism has no such compulsion.
In Judaism, the only things which are required of everybody are the 7 basic Noahide laws:
1)No Idolatry
2) No Murder
3)No Theft
4)No Sexual immorality
5) No Blasphemy
6)No Eating the limb of a live animal
7)The requirement to set up courts of Justice
However, thats it- one does not have to take on any of the ritual observances of Judaism. Therefore, conversion was always supposed to be based on the conviction of the convert, and never for alterior motives such as Marriage, money, etc. Therefore, the Jews were always very reticent to accept such converts who converted for reasons other than true desire.
That the Hasmoneans converted, by force, the Idumeans, the Rabbis were not happy- as well as with the concentration of power.
Out of the Idumeans will come Herod the Great and many collaborators with the Romans, which will help to destroy the Jewish state instead of strengthening it.