Rather, there is a certain tension that none of the candidates wish to acknowledge here: all three have plans on ISIS that are some version of the status quo. But the status quo is unpopular; it's not an easy sell to ask Americans to look at the Middle East and conclude "let's do more of what we're doing now."
So, rather than acknowledge that they want to continue the status quo, all three candidates are describing policies that are almost exactly the same as Obama's while striving for rhetoric that suggests drastic differences where few really exist. Clinton is seeking to dress up the status quo as a new and more hawkish course, while Sanders wants to dress up the status quo as a new and more dovish course.
Clinton proposed a "three-point plan" of three things the US is already doing. Sanders merely praised Obama and then pivoted to criticizing Republicans. O'Malley urged, "We need to develop new alliances" against ISIS, though I'm not sure I could name a country in the Middle East, other than Iran or Syria, with which we are not already in some form of alliance.
The Republican candidates, by the way, are doing the exact same thing: their plans are broadly identical to Obama's. But this is easier for them to manage, in political terms, because they can criticize Obama and then present their plan as novel. Democratic candidates are in the awkward position of feeling they can neither fully embrace nor reject Obama on these issues.