With the Middle East, things are never what they seem on the surface. In this case, what is not so obvious is that Qatar has recently refused [1] to tow the anti-Iranian line of the Saudi-led Gulf states, who consider Iran to be their regional rival and mortal enemy. And that most of the Gulf states are already fighting regional proxy wars [2] using "rebel fighters" (if we are charitable about the wording), many of whom are in fact groups of former or future ISIS soldiers [3]. Hence, the hypocrisy here of the Gulf states accusing Qatar of supporting terrorism, when these states are engaging in the very same activities. Without more detail, it seems that Qatar's actual crime is standing up to the Saudis or just not towing the same line on foreign policy.

[1] http://www.businessinsider.com/r-gulf-arab-row-rattles-trump... [2] https://www.theguardian.com/politics/2016/dec/07/boris-johns... [3] http://www.independent.co.uk/voices/hillary-clinton-wikileak...