Will World War 3 break out?

The war between Israel & Hamas forces has been going on for over a week now. Fighting between the two sides has continued ever since Hamas launched a sudden missile attack on Israel. In response, Israel has intensified its attacks on the Gaza Strip. It is feared that Israel may invade Gaza at any time.’
Meanwhile, there is fear that this Israel-Hamas war will spread throughout the region. 
Already, Arab countries have taken a stand in favor of Hamas. 
At the same time, the United States, the world power, has taken a pro-Israel position as always. This is where the situation is seen when the war will expand further.
Meanwhile, Iran's opinion on this issue is very important. 
Iran's Supreme Leader Ayatollah Ali Khamenei has warned that if Israel continues its offensive in Gaza, no one will be able to stop Muslims around the world. 
This comes not as an admonition but as a warning to immediately stop the attack on Gaza.
Meanwhile, Iran has made another allegation in the matter. 
It has  accused the United States of already interfering in the Palestinian issue.If the US intervenes, Iran is also likely to counter. 
So, now the countries of the world are afraid that this war will spread to the entire region.Hamas refuses to release Israeli hostages despite UN insistence. Hamas was the first to attack, firing 5,000 missiles at once. Despite US advice that it would not be right to invade Gaza, Israeli Prime Minister Netanyahu has been adamant that we will destroy Hamas completely. “Hamas started it, we will finish it,” he asserts..In this way, the intervention of the world countries is increasing day by day in the war between Israel and Hamas forces. 
Because of this there is also fear that this will lead to the next world war.World War 3? Nobody want it!