Question #1: Spanish Citizenship
"Now that a Jew who can demonstrate Sefardic origin is eligible, at least in theory, for Spanish citizenship, is it permitted to take advantage of the offer?"
Question #2: Frankfurt Flights
"May I change planes in Frankfurt?"
Question #3: Berlin Walls
"I understand that there is a large kiruv community now in Berlin. But is it permitted to live there?"

The Jewish nation has been wandering in golus for a long time. In some countries we fared better than in others. But, even in the best of places, we still have to remember that golus is golus. There is some discussion in halachic literature concerning some of the lands where we found ourselves during this long exile. Specifically, is one permitted to return to those countries where the Jews suffered unspeakable atrocities?

Returning to Spain
The Jews of Spain were expelled in 1492, after having lived and prospered there for over a thousand years, and possibly much longer. In the time of the rishonim, during the "Golden Age of Spain," not only did the Jewish community thrive in the physical and material sense, but it also flourished there spiritually. Unfortunately, the last hundred plus years of Jewish residence in Spain became a complete nightmare, including riots, torturing and murdering by the Inquisition, and the subsequent expulsion.
Several poskim deal with the question whether it is permissible to live in or visit Spain. The issue at hand is that there is an oral tradition that the Spanish exiles issued a cheirem, a severe form of oath, forbidding the return to Spain. One such tradition exists in the Toledano family. Rav Y. M. Toledano, the former chief rabbi of Tel Aviv-Yaffo, writes that his family originated in the Spanish city of Toledo. After the expulsion, they accepted upon themselves not to return to Spain, and to emphasize this to all future generations, they changed their family name to Toledo-no, meaning "no to Toledo" (the word "no" in Spanish is the same as in English) [cited in Tzitz Eliezer, volume V, #17 and Yabi’a Omer, volume VII, Yoreh Deah #14].
However, the poskim note that there is nothing explicit in any of the major halachic works indicating that such a cheirem was ever accepted. The Abarbanel, who was exiled from Spain, does not mention anything about a cheirem, although he writes extensively about the expulsion. Additionally, there is nothing found in any of the vast writings of the Beis Yosef concerning a prohibition against returning to Spain, even though he fled Spain as a child with his family (see Tzitz Eliezer and Yabi’a Omer ibid.).

Possible Proof that there was a Cheirem
Rav Eliezer Yehudah Waldenberg writes (Shu"t Tzitz Eliezer, volume V, #17) that he believes he found a very strong allusion to the existence of such a cheirem. He cites a responsum from Rav Moshe ben Yosef Trani, otherwise known as the Mabit, who was born eight years after the Spanish expulsion. The following question was posed to the Mabit:
A particular city had numerous congregations, each of which treated itself as a separate community, based on its particular country of origin. Most of the people of the city decided that a new émigré would be considered to be part of the community in which he and his father had been born. For example, if a newcomer and his father were born in Italy, he would join the Italian community, and the grandfather’s nationality played no part in the decision. Thus, it was completely possible that someone whose family had been in Spain for hundreds of years and whose family was essentially Sefardi, or originating in Spain, would be considered Italian, if the last two generations had been born in Italy.
The problem with this arrangement was that the members of the Spanish community were opposed to it. The Spanish exiles had immigrated to various countries, and virtually all of the Spanish newcomers to this particular city had been out of Spain for at least two generations. (Keep in mind that when this shaylah was posed, it was a mere seventy years after the expulsion.) Therefore, the members of the Spanish community felt that it was not fair that someone whose forefathers came from Spain should be forced to join other communities, just because he and his father had been born outside of Spain. So, the question posed to the Mabit was whether the Spanish community of that city had to follow the arrangement.
It must be noted that this situation involved a financial question as well. Obviously, the more members any particular community had made that community more financially stable. Therefore, this rule put the Spanish kehilah at a disadvantage.
The Mabit contends that it is certainly within the rights of the Spanish kehilah to protest, as they are the ones who stand to lose. He then says that one cannot argue that things will even out among the communities, and just like the Italian kehilah will get those of Spanish descent (who were second generation Italians), the Spanish kehilah will similarly end up with Jews of Italian descent (who were second generation Spaniards). This is because, writes the Mabit, "it is known that no Italian who both he and his father were born in Spain will ever come to this city, for there have not been any Jews in Spain for the last seventy years, and we are certain that no Jew will ever live there."
After citing this responsum of the Mabit, the Tzitz Eliezer wonders how the Mabit knew that no one would ever come from Spain. Rather, it must be that the Mabit was aware that there was a cheirem in place, forbidding Jews to return to Spain.

Doubtful at Best
Some of the poskim take the position that, notwithstanding the fact that no halachic work mentions explicitly that a cheirem was ever accepted, it should be considered as a safek cheirem, a cheirem under question, which, according to some Rishonim, must be obeyed. This would imply that it is forbidden to go to Spain.
However, several poskim note that the concept of safek cheirem applies only when there was a cheirem, but we are uncertain as to what was included in the cheirem. However, where we are unsure whether a cheirem ever existed, this is not a safek cheirem. Therefore, these poskim permit going to Spain (Shu"t Minchas Elazar, volume V, #11; Shu"t Yabi’a Omer, volume VII, Yoreh Deah #14). However, Rav Waldenberg writes that, although his initial reaction was to permit going to Spain, afterwards, he reconsidered and wrote that, since a rumor exists that such a cheirem exists, perhaps the practice not to go has the force of a minhag Yisroel that should be observed.
Spanish Citizenship
At this point, we can address our opening question: "Now that a Jew who can demonstrate Sefardic origin is eligible, at least in theory, for Spanish citizenship, is it permitted to take advantage of the offer?"
As we have seen, most authorities permit living in Spain. Even taking into account those who forbid it, I have seen no reason to prohibit acquiring Spanish citizenship. If any of our readers know of someone who has forbidden it, please let me know.

A Cheirem on Germany
After the devastation of World War II, a rabbinic council met and discussed whether to issue a worldwide ban against Jews returning to Germany. Although several rabbonim were in favor, one rov, Rav Meshulem Roth, penned a responsum (Shu"t Kol Mevasser, volume I, #13) explaining why he felt that such a cheirem was halachically wrong.
He prefaces his remarks by saying that from a political, logical and moral standpoint, such a suggestion is correct. There is no doubt that, after such an unprecedented and horrific destruction wrought by the German nation on our people, even without a declaration of the rabbonim, every Jew should refrain from treading upon contaminated soil. Rav Roth then cites two halachic reasons why such a ban goes against halachah.
1) Both the Rosh (Shabbos 2:15 and Niddah 10:13) and the Rivash (Shu"t #271) take issue with decrees instituted by the Geonim and early Rishonim that were meant either for all of Klal Yisroel, or for the Jews of a particular country. They maintain that after the Gemara had been sealed, no one has the authority to issue decrees that are binding on all Jews. Although there are Rishonim who contend that the Geonim did have the power to enact decrees on all Jews (Magid Mishnah, Chametz Umatzah 5:20), everyone agrees that, after the Geonim, this is no longer feasible.
2) The Gemara (Avodah Zarah 36a) states that we may not enact decrees on the community, unless the majority of the people will be able to follow through. This Gemara is cited both by the Rambam (Hilchos Mamrim 2:5) and the Shulchan Aruch (Yoreh Deah 228:50 and 334:15).
Rav Roth concludes that if we find that the Rishonim had to search for excuses why it was permitted for Jews to live in Mitzrayim, even though it is possibly a Torah prohibition (as we discussed in a different article, now available on the website =RabbiKaganoff.com), it goes without saying that to impose a decree against returning to Germany is certainly something with which the Jewish nation will not be able to comply.
At this point, we can return to our other opening questions:
Frankfurt Flights
"May I change planes in Frankfurt?"
Berlin Walls
"I understand that there is a large kiruv community now in Berlin. But is it permitted to live there?"
According to Rav Meshulem Roth, there is no cheirem against doing so.
Let us hope that we will soon merit seeing the kibbutz galiyos, the ingathering of the exiles, and the rebuilding of the Beis Hamikdash, bimheirah biyameinu!
This Shiur is published also at Rabbi Kaganof's site