How dangerous is this confrontation with Moscow?

If the US, plus Britain and France, launch airstrikes/Tomahawks at Syrian airbases known to have chemical stocks, is this going to lead to a serious, and therefore potentially extremely dangerous confrontation with Russia? Donald Trump is playing the Big Stick Game and warning Moscow that missiles, very smart ones, will soon be on the way. I can't recall an American president saying anything like that before. His tough stance is supposed to put Russia on notice that the US, with or without anyone else's support, WILL attack Syria. The last time he pressed the button for a Tomahawk missile strike against a Syrian airbase - last year - Moscow grumbled and muttered but did nothing. This time, Moscow is warnig that it will shoot down any US missiles aimed in Syria's direction. So this time it's different. The Russians are saying they will attack American missiles. This puts the whole situation into a different stratosphere. And therefore potentially putting us all into a graver place. Syria clearly used chemical munitions to hit Douma. I can't imagine there is anyone - especially not Moscow - who disbelieves that. Russian troops operate alongside Syrian forces. They know what's going on. They must have approved the chemical airstrike, unless Bashar Assad, for once, failed to liase with them. So Trump is right. Assad has to be punished. But the problem is we have two big egos here, Trump's and Putin's. Neither wants to back down and both want to prove that their respective military capabilities are the best. IF Russia succeeds in shooting down any of the US missiles, or much worse, if Russian/Syrian forces shoot down US aircraft flying over Syria, I believe the US will not take this calmly. They will send in aircraft to destroy Syrian air defences which, of course, are Russian-made. That's where it could get very dangerous very quickly unless Moscow blinks and backs down. In my gut I think Trump feels that for all his bravado Putin will do just that, back down. If Putin takes on the US in Syria in a big way, he will definitely lose. Can Putin afford to be seen to lose against the US? I doubt it, but before we get to that point, there are going to be a few days of scary escalation. The end result? Assad will still be in power, Putin will still be his main backer. But Trump will have set a new marker. The US is not going to go away from this one, despite what Trump said only a week or so ago about pulling out US troops. Assad will never again, I hope, feel safe from Trump's big stick.