And you will hear of wars and rumours of wars. See that you are not troubled; for all these things must come to pass, but the end is not yet.
(Matthew 24:6)
This is not new. I agree that both Putin and Trump are dangerous men, and they are joined by other dangerous men, such as Xi Jinping and Kim Jong Un, but I don't think WW3 is imminent. We are being softened up for more spending on defence, which will shore up flagging economies worldwide, and talk of conscription and so on is spreading fear, so populations will accept it.
I'm not blindly optimistic, but neither do I think that we should stop enjoying our lives. It may be that in 5-10 years time, Putin (who by then will be a very old man) will be in a position to invade another country, and if that happens, the odds are that the other country will have rearmed too. Sands shift all the time. The odds on Putin invading the UK are vanishingly small, and we are cementing allegiances with other democracies that he has arguably been working to weaken.