Two people have arrived from outside the fold to have a Portion named after them: Yithro and Balak. There is a great similarity between them. Both of them followed with suspicion and curiosity that new Nation which went out of Egypt, and both of them reached practical conclusions. But, find the differences: Yithro was enthusiastic and decided to help and join them, whereas Balak decided that the Nation should be cursed and fought against. Each of them was etched forever in history, according to his good or bad motive..
When something dramatic happens - we must decide where we are in the story. Indeed, Balak could have chosen differently, and then we would have had a different Portion after his name, just like in Yithro's case: "And Balak heard all that G-d did to Moshe and to Israel... and Balak and his sons came to Moshe...". Similarly, Yithro could have chosen differently, and then we would have read about him, just as in Balak's case: "And Yithro sent messengers to Balaam", to curse Israel.
Rabbi Shmuel Polack writes that there is an important message here: Faced with an absolute truth, one cannot remain indifferent. One must do something. One does not stay in the grey area. We see it globally - how different countries react to the existence of the State of Israel differently - but we also see it personally, in our daily lives. The two decisions stem from the same place in our mind: something great is happening, and we cannot stay indifferent to the events. We want to do something. May we merit to choose right.