Or so argue Israel apologists. But it's a dishonest argument, beginning with the fact that some of its premises have long ceased to be true.
The bulk of the counterargumentation has already been provided by The Magnes Zionist. To put it succintly, the German constitutional clause which granted citizenship to people of German stock living in Eastern Europe, including Russia, was designed to cover cases of expulsions and forcible transfers. This was later extended to people of German extraction living under oppresive Communist regimes. It did not apply to the numerous Volga German communities in Argentina or Brazil (for instance). It was a temporary remedy. As TMZ comments:
In fact, while couched in ethno-national language, the German “right of return” was not an open invitation to ethnic Germans to help rebuild a German commonwealth, but a humanitarian gesture to rescue co-ethnics from “oppression” under Soviet rule. The rhetoric of ethnic solidarity on the part of German conservatives was also an attempt to legitimize a German ethnic nationalism after its being discredited as a result of the Nazi period.
In any event, the “right of return” was limited spatially to those ethnic German living the Soviet Union and temporally to those who suffered as a result of the expulsions and living in a hostile environment. With more liberal emigration laws, and then the demise of the Soviet Union, the “right of return” was challenged both by liberals, who were opposed to preferential treatment of co-ethnics, and by conservatives, who feared the influx of Russians of German descent. As a result of legislation in 1993, preferential treatment in immigration was almost entirely curtailed.
May it also be added that despite the difficulties in acquiring nationality, non-Germanic foreigners did apply for, and obtain, it in large numbers. According to official figures, between 1995 and 2004 1,278,524 foreigners gained German citizenship -- 608,450 of them from Turkey alone. The comparable figure would be 10,000 non-Jews gaining Israeli citizenship each year, which we know is not happening.
But I'd like to point out two additional aspects in which Israel's citizenship law is radically different from other countries'.
In the first place, the German, Irish, Greek, etc., laws refer to people who emigrated from their respective countries at a time when nationality, citizenship and ethnicity were approximately coincident, and the respective countries were fairly homogeneous. Irish emigrants to the United States, for instance, tended to be white English-speaking Catholics, not brown-skinned Sikhs who spoke Punjabi at home. Same with Germans, who were white and German-speaking. The internal differences that did exist (for instance, between Protestant and Catholic Germans) translated into no additional rights or restrictions under the law. And the current versions of those European laws make no difference by race, religion or mother tongue.
This is not the same as the case in Israel. When Israel was founded, it was already inhomogeneous; it already comprised a fairly large Arab-speaking minority of the Muslim, Christian and Druze faiths alongside the Hebrew speaking Jewish majority. Furthermore, the State's creation itself originated a diaspora -- people who were born in the territory on which Israel was declared, and whose ancestors had been living for generations there, but who were not covered by the Nationality Law. Those (forced) emigrants are the equivalent of the Irish, German or Greek emigrants whose children have the right to citizenship under the respective laws. However, the Israeli law doesn't grant them the right to citizenship accorded to Jews. It's like if the German law accorded citizenship to Protestant emigres, but not to Catholic ones.
The second big difference is that while in Germany the process to become a citizen may be long and tiresome, down the road there's always a point from which you have exactly the same rights as a blue-eyed, blond and Christian German. A child born in Germany to a foreigner who has been a legal resident for 8 years, for instance, is granted temporary citizenship, but he must apply to retain it when he turns 23. I don't agree with such a provision; I prefer the Argentinian system whereby a child born in the country is forever a citizen. That said, once that German-born person successfully re-applies for citizenship, he becomes undistinguishable from any other German, and he can pass his German nationality on to his offspring on an equal footing with all other Germans.
That's hardly the case in Israel, where an Israeli-born Arab is a citizen but does not enjoy the rights that can be acquired through the Law of Return -- which detracts from his ability to remain a citizen. Thus, Israel's Nationality Law provides that:
# 11. (a) Where an Israel national -
* (1) became an Israel national on the basis of false particulars; or
* (2) has been abroad for seven consecutive years and has no effective connection with Israel, and has not proved that his effective connection with Israel was severed otherwise than by his own volition; or
* (3) has committed an act constituting a breach of allegiance to the State of Israel,
the District Court may, on the application of the Minister, annul his nationality.
This is not egalitarian, because the Arab Israeli who pursues a career abroad has his nationality revoked and loses any further right to it, while a Jewish Israeli in a similar situation can reapply for it under the Law of Return. Similarly, only the children of an Arab Israeli can apply for Israeli citizenship, while in the case of the Jewish Israeli, his children and grandchildren --at the very least-- can do so, again because of the Law of Return, and the right extends to further generations provided they marry other Jews.
In sum, despite the superficial similarities existing between the German and Israeli nationality laws, the results have been radically different, the former creating an ever more diverse society with equal rights for all, and the latter ensuring Jewish supremacy in a society with two de facto citizenships, one of higher quality than the other.