This is one of those questions that seems a bit vague. Of course we 'can,' but is there something in particular that concerns you?
The Iranian situation is a risk for world peace, although whether it is likely to trigger a world war is questionable: what one needs historically for a real "World War" is a couple of really large alliances, so that belligerence for one pair of nations drags in more and more countries to the fight. (World War I is the classic example: a Yugoslav assassinated an Austrian, causing Austria-Hungary to issue an ultimatum to Serbia, causing Russia to defend the Serbs, bringing Germany in to defend the Austrian-Hungarians, bringing England and France in to oppose Germany. The war contagion kept spreading over the next four years.)
In today's multilateral world, it may be a bit harder for such conflicts to spread quite so quickly and widely: military power is much more distributed today than at the beginning of the twentieth century, and there are a number of power blocs, with ties probably looser on average than they used to be. Trade is also much more multilateral, which means that war is more obviously 'bad for business' than it used to be.
Still, one should never say never. No-one expected World War One before it happened--nor did anyone expect it to last four years, nor that it would decimate a whole generation of European youth, impoverish whole societies, and begin the complete de-stabilization of the existing world order at that time.
And as climate change continues to degrade the conditions to which our agriculture and infrastructure are adapted, we can expect many potential causes of war to follow: people (it is often said) will "raid before they starve." For more, see: