Serious WWIII - Whats your thoughts?

Even if there's a war with Iran, it's highly doubted that it would cause any sort of World War 3 conflict. Russia, China, and other larger powers understand that any large conflict between the U.S. and each other would result in sure destruction and major losses on both sides. Due to that, the issue will most likely remain between Iran, its smaller allies, the U.S., and the U.S.' allies. While at this moment it seems very possible for a war with Iran due to their provocations, terrorist activities, and destabilization efforts in the Middle East, such a war wouldn't really lead to "World War III." A war of that scale would be similar to the Iraq War, or if the U.S. decides to be smart they could win very quickly, but at the cost of many Iranian lives (strikes, bombs, etc.)