Ruling on jihaad
Question

                Is jihaad considered to be fard
      ‘ayn [obligatory on all individuals] now, when the rights of Muslims have been
      violated by foreign invasions and in other ways? What is the ruling on those who are not
      engaged in jihaad, who cannot do anything, but if they were called upon they would respond
      and fight in jihaad for the sake of Allaah, but they are prevented by the current
      circumstances of the ummah, such as the lack of rule according to sharee’ah? Please
      respond, with evidence (daleel).
Praise be to Allah.Jihaad to make the word of Allaah supreme, to protect
    the religion of Islam, to enable spreading the faith and to protect the things it holds
    sacred, is an obligation upon everyone who is able to do it. But this necessitates
    organizing and sending armies, lest it result in chaos leading to bad consequences. So
    initiating it is one of the tasks of the Muslim ruler, and the ‘ulamaa’ should
    encourage it. If jihaad begins and the Muslims are mobilized, then everyone who is able
    should answer the call, sincerely for the sake of Allaah, hoping for truth to prevail and
    to protect Islam. Whoever holds back from that when the call has been made, with no valid
    excuse, is a sinner.
And Allaah is the source of strength. May Allaah bless our Prophet
    Muhammad and his family and companions, and grant them peace.