Case:


Ruling: It is not clear that the mother is an aputropus (legal guardian), as she was not appointed by beit din, but let us assume that she is based on the law of the land. An aputropus is not allowed to even enter a court case against the children, lest they lose the case, and if he did, it is not binding (Shulchan Aruch, Choshen Mishpat 290:14 and S’ma ad loc.:33). Certainly, relinquishing the children’s rights without direct gain for them is not allowed or even binding after the fact. If the father wants to claim that the mother obligated herself to support the children and thus he is exempt, he must prove this is true and also prove that she is capable of carrying this out reasonably. (Her financial situation does not seem to support that claim). Until he does so, he must support his children.
We must look into the possibility that, assuming the stipulation to not support his children is invalid, this invalidates the get, which seems to have been conditional upon completion of this legal step. There is a major halachic discussion about the case where a husband makes a condition before agreeing to a get but then has the get written and given without repeating the condition (see opinions in Pitchei Teshuva, Even Haezer 143:1). While most opinions validate the get, much of that is based on the assumption that at the time of the get, the husband declared that the get was being performed without condition. This, for whatever reason, does not seem to have been done in the case of this get.
However, it appears that the wife actually fulfilled his condition. He demanded that she make a declaration before a secular judge, which she did. He should have known that this would not be a halachically binding act. The fact that beit din is now upholding the children’s rights does not contradict that. He also seemed resigned to the possibility that he would have to pay the children and therefore had his wife obligate herself to pay 10,000 liras. He may decide to enforce that in court, which will be out of the domain of beit din. The important point is that this situation does not impact upon the validity of the get. Furthermore, the husband never formulated his demand for the financial considerations as a condition on the get but as a step that he demanded be done before he agreed to the get. As such, the get was in no way conditional.