Israel is typically a western country and as such has typical western birth rate. However, Hasidic Jews and to a lesser degree the Arab population are both expanding with 10 children per household in many cases. This in itself wouldn't be a problem but due to the closed nature of both society's (especially the Hasidic Jews), we end up with largely ignorant adults who are changing the demographic of the country.
Statistically a non-religious Israeli household contributes a large percentage of its income in terms of taxes. It serves in the Army and has a net positive impact on the economy. Hasidim specifically have the inverse impact. They take more in terms of benefits than they contribute to the economy and, due to their refusal to partake in school standardization, their children would be a major burden on society too. Their destructive impact on politics is even worse.