In the shallow definitions of the Religious-Zionist and Charedi street, some say Rav Kook was a Religious-Zionist and some say he was Charedi except for his stance regarding Eretz Yisrael. Both are wrong. Maran Ha-Rav Kook was Charedi from the sole of his foot to the top of his head, and even more than this: he was more Charedi than the Charedim. It is clear as day to anyone who knew him and to anyone who learns his books. And the same is true of Rabbenu Ha-Rav Tzvi Yehudah, who was known by many people who are still alive today.
Perhaps you will ask: But what about Rav Kook's attitude towards Eretz Yisrael, Zionism and the Redemption? These issues do not detract from his Charedi-ism but add to it. Maran Ha-Rav Kook did not invalidate Charedi-ism with his views but added to it an additional, forgotten level.
For what is Charedi-ism? Fear of Hashem, being strict on oneself to perform difficult Mitzvot as well as easy ones, self-sacrifice for learning Torah, distancing oneself from corrupt culture, providing children with pure education, etc. If so, Maran Ha-Rav Kook was certainly Charedi.
In fact, liberal Orthodox groups in Israel declare that although they greatly respect Maran Ha-Rav Kook, he is not the guiding force for them. Each issue is decided on its own merits. As a result, they reject Charedim as being outside of their "box", they are against stipends for Charedi Yeshivot and they spread many lies about the Charedim. There are certainly many problems in the Charedi world, and their Rabbis acknowledge as much, but this is no reason to cast aspersions at them.
Furthermore, Maran Ha-Rav Kook was more Charedi than the Charedim. How so? He was the Divine agent for working not only to perfect the individual, but also to perfect of the entire community, i.e. the revival of the Nation of Israel in its Land, which is a more difficult realm than working to perfect an individual. Matters relating to the entire community are always more complicated than matters relating to the individual. It is more complicated to be David, King of Israel, who was completely holy, than an individual Tzadik hidden away in one's room.
And if a person who is closed off in his own individual world, as we were in the Exile, must be equally careful in performing easy and difficult Mitzvot, then this is all the more so true for we who are involved with matters regarding the Nation, the army, the economy, politics, societal issues, etc.
May we – students of Maran Ha-Rav Kook – serve Hashem with all our heart, with all our soul and with all our might.