You are mixed up. The two-thirds cut off will be of the whole world. That’s why Zech 14 says the remnant nations will go to Jerusalem every year for the Feast of Tabernacles.
Wrong grasshopper. That is written to Israel, not the world. I suggest you do a bit more study. Nearly every commentary I have ever read refer to this as Israel’s punishment via the antichrist during the tribulation, in which the Jews will be persecuted by the AC and God will bring them through the fire, is the fire of the trib. You are simply w-r-o-n-g!! As for the remnant nations are referring to them going to Jerusalem every year for the Feast of Tabernacles DURING THE MILLENINUM REIGN OF CHRIST JESUS on earth AFTER the Tribulation. If you would do a bit more study you will find in the OT several verses referring to the nations going to Jerusalem during the Millennium Reign. The 10 people asking a Jew to allow them to go with him to Jerusalem verse applies to this. There are others. You are wrong. Sorry.