The Mishna had stated: A man may force all of his family members to go up to Eretz Yisroel, but he may not force them to leave Eretz Yisroel. A man may force all of his family members to go up to Yerushalayim, but he may not force them to leave Yerushalayim. This applies to both men and women (a wife can force the husband).

The Gemora explains that these halachos are based upon the mitzvah of furthering the settlement of Eretz Yisroel.

The Ramban says that this mitzvah is a Biblical commandment. The Rambam omits this mitzvah is his Sefer Hamitzvos. There are those that explain that the Rambam holds that it’s only a Rabbinical mitzvah. Other say that the Rambam holds it is not a mitzvah at all; the only reason why a man can force his family members to move to Eretz Yisroel is because this way, they will be able to fulfill the mitzvos which are dependent upon the Land of Israel.

The Ritva writes that the applications of the Mishna apply to nowadays also. Proof to this is from the fact that Rebbe incorporated these halachos into the Mishna even though he was living in the times after the destruction of the Beis Hamikdosh.

Tosfos cites Rabbeinu Chaim Kohen that there is no mitzvah nowadays because there are many mitzvos there which entail many punishments, and it will be impossible for one to be careful regarding all of them. This can be simply understood to mean that although there might be a mitzvah to live in Eretz Yisroel, it is simply not worth it, for one will lose out by transgressing many aveiros there. Reb Avi Lebowitz (and afterwards I found this logic in the Beis Halevi) explains a little differently: Rabbeinu Chaim is actually describing the mitzvah of living in Eretz Yisroel to be for the purpose of fulfilling the mitzvos that apply there. If one were to live in Eretz Yisroel without properly performing the mitzvos, they are not only losing out on these additional mitzvos; they are also not fulfilling the mitzvah of living in Eretz Yisroel.