There is no doubt that in future there will be a World War 3. Cause if World war 1 and 2 can happen then why not world war 3. And another reason that the world war 3 will happen some day cause there are many nations who are actively increasing, modernizing and also secretly getting or possessing WMD. After all these all WMD is for to use some day. Its only a matter of how it will triggered, what will be reason for its trigger, who will trigger the first war and then the scenario followed by it. One could not completely ignore and live thinking that there wont be any 3rd World war. The reason being many. And slowely and gradually the world is moving towards it. We all know even the world war 1 was started due to a simple reason. But in todays scenario the issues are much bigger. And could possibly be the reason for any future war. Lets see few reasons.
Iran. Iran is a country which is continuously professing the destruction of Israel. This is due to their political system based on Religion and its conservative ideology. And for this they are actively involved in developing nuclear weapons. This kind of ideology cannot go in a day or say in years. Cause they them self thrown a system of Shah and adopted a more intricate Islamic ideology. This is a country which cannot be trusted that they will remain peace and wont provoke or start any war with Israel. As we have already seen from their top most authority. Suppose if Iran develops nuclear weapons or in case releases one of its long range missiles to Israel then there will be catastrophic effect. Which in turn will not leave any chance before Israel to go for war with Iran. And in this US or EU will definitively jump into it to support Israel. But since non of the gulf countries are friendly to Israel then there could be a possibility of Gulf countries to side with Iran forgetting their Shia-Sunni rift for a while as Israel is also their common enemy. And thus a chain reaction.
Second is India Pakistan conflict. We all know Pakistan is a rogue state. They openly preach the policy of using nuclear weapons against India for any kind of threat. And due to this one could not completely ignore that Pakistan wont do such acts. Cause let see one example. Despite of going for war with India and loosing many a times they still go for war with India in some or the other way. the last one was Kargil. Reason being either they dont have any solution nor any direction. Then how could one be rest assured about their command on WMD decision. And for this eventually there could be a war with India Pakistan and other countries joining it.
Israel Palestine issue. The solution for Palestine issue is to have a separate country for Palestine. But the difficulty lies in the west bank. Palestine wants a country carved out of present Israel including Jerusalem. Reason being in Jerusalem there is a Holy mosque "Al-Aqsa Mosque". This is the 3rd holy mosque of Muslims. But also the most holy place for Jews. During the time of invasion by Muslims to this region they captured this place and made a mosque named as Al Aqsa Mosque. For Jews this is the place where Abraham brought his son Issac for sacrifice "Mount Moriah". The reason is will Israel give this mosque or place to Palestine or Muslims. As its the only holy place to Jews faith. Or will the Muslims will leave this mosque to Jews. Dont think so. And could possibly be the reason for conflict and its escalation some day.