I've read this Hadith on his Link
https://www.al-islam.org/an-overview-of-mahdi-s-government-najimuddin-tabasi/imam-al-mahdi-s-mode-conduct-enemies#f_319c07f8_24
This is very shocking
(Quran) “While to Him submit whosoever there is in the heavens and the earth, willingly or unwillingly.”
The Imam (‘a) replied: “This verse has been revealed about al-Qa’im (‘atfs); it is when he rises up against the Jews, Christians, Sabeans, materialists, those who turned back from Islam, and the infidels of the east and west while offering Islam to them. He will command anyone who accepts it out of his own will to perform the prayers, pay the zakat and do whatever a Muslim ought to do. He will behead anyone who refuses to become Muslim so much so that not a single infidel will remain in both the east and west of the globe.”
‘Abdullah ibn Bakir asked: “May I be your ransom! There are a lot of people on earth. How could the Imam (‘atfs) make them Muslims or behead them?”
Imam al-Kazim (‘a) replied: “If God wills something, that which is few will become plenty and something plenty will become few.”
Ayyashi, Tafsir ‘Ayyashi, vol. 1, p. 183; Nur ath-Thaqalayn, vol. 1, p. 362; Ithbat al-Hudah, vol. 3, p. 549; Tafsir Safi, vol. 1, p. 267; Bihar al-Anwar, vol. 52, p. 340.
Any thought?