With war with Iran becoming increasingly likely with each missile attack, the big question is whether this will escalate into World War III, with China and Russia jumping into the big brawl. Some think, maybe:
  https://www.asiatimes.com/2020/01/article/could-china-take-irans-side-in-a-war-with-us/

“The next question is, how will regional powers react to a US-Iran war? China and Russia already seem to have answered that question via their war games in the Gulf of Oman last week, and the signal to the US is that Iran is not isolated and has powerful allies. Indeed, last year retired US Army Colonel Douglas Macgregor already warned that a war with Iran could draw in China and Russia. Currently, China’s reaction is to urge both Iran and the US to maintain calm and de-escalate tensions, and closely monitor the situation. Beijing does not want war and needs Mideast stability to pursue the Belt and Road Initiative Eurasian integration plan. It has large stakes in Iran’s stability: It is the largest buyer of Iranian oil, China is Iran’s largest trading partner, and Iran is a key geographic node for the BRI. Up to now, China has tried to balance its relationship with Saudi Arabia and Iran in the Middle East and set up a firewall between the two, although Iran is more significant in China’s strategic calculus given the fact Saudi Arabia and other Arab Gulf countries are still under the US security umbrella and host US military bases. China is also against further Western-sponsored regime change in the region, and Iran is an important partner in counterbalancing US hegemony and the drive toward a multipolar world. ‘It’s about China’

Should a US-Iran war break out and the Iranian government is overthrown, it would be devastating for China’s regional interests. As Robert Kaplan wrote in a New York Times article titled “This isn’t about Iran. It’s about China,” the current US-Iran standoff is about something much vaster. Geography matters in geopolitics and the Gulf of Oman separates not only Oman and Iran but also Oman and Pakistan, where China has completed a state-of-the-art port at Gwadar.  It is a hinge uniting the Middle East, the South Asian subcontinent and East Asia in China’s BRI.”

     Still another option, from a source that I do not often agree with, holds that China and Russia will not jump in because the US is so weak it could not fight its way out of a wet paper bag, so Iran will need no help …ok, a wee bit of exaggeration, maybe a dry paper bag, but the basic point is there:
  https://russia-insider.com/en/russia-wont-intervene-iran-us-will-lose-war-against-iran-beginning-end-us-empire/ri28134

“So what is really happening now? Folks, this is the beginning of the end for the Empire. Yes, I know, this sounds incredible, yet this is exactly what we are seeing happening before our eyes. The very best which the US can hope for now is a quick and complete withdrawal from the Middle-East. For a long list of political reason, that does not seem a realistic scenario right now. So what next? A major war against Iran and against the entire “Shia crescent” ? Not a good option either. Not only will the US lose, but it would lose both politically and militarily. Limited strikes? Not good either, since we know that Iran will retaliate massively. A behind the scenes major concession to appease Iran? Nope, ain’t gonna happen either since if the Iranians let the murder of Soleimani go unpunished, then Hassan Nasrallah, Bashar al-Assad and even Ayatollah Ali Khamenei will be the next ones to be murdered. A massive air campaign? Most likely, and initially this will feel good (lots of flagwaving in the USA), but soon this will turn into a massive disaster. Use nukes? Sure, and destroy your political image forever and not only in the Middle-East but worldwide.”

     I would not be so hasty and dismiss the nuclear option; I am confident that we will see these bombs being freely used in the coming war. Further, there does not seem to be any turning back now, for Iran will keep attacking to maintain honour, and the US, and the world, will face the prospects of the Straits of Hormuz being blocked, which would close one of the most strategically important trade routes in the world: not good for business.

     I have been saying this for a long time; get prepared for war. If you know any, talk to old timers about how they survived the last big one. I would recommend putting away non-perishable supplies now, maybe in secure locations. As a kid I remember talking to an old Italian, who told me that he survived the deprivation of World War II, because under his house he had secured a good supply of olive oil, which he consumed each day (fats and oils) and whatever food he could find. Hopefully it will not get that bad, too quickly.  But, today, anything is possible.