The pertinent part of the interview begins at about the 2 minute mark. He says, in short, what Russia is doing may save the lives of Christians. If the Assad government were allowed to collapse, it would mean the slaughter of Christians, and an increase of refugees. He no doubt takes this view because his organization, Samaritan's Purse, has been on the ground in Syria, trying to help the people.
If you ask any Syrian Christian about this, you will find that they support Russia's intervention.
Franklin Graham is a prominent Evangelical Protestant leader in his own right, and the son of Billy Graham.
See also this article from Christianity Today.
Update: Here is a video of Franklin Graham meeting with Patriarch Kirill, in which he expressed his thanks to Putin for supporting the Assad government in Syria, because if Assad is removed, the Christians will be slaughtered:
