One could ask similar questions about the Americans, or the Russians. America hasnt won a war since 1991. Russia hasnt won since WWII.

Winning wars, as opposed to just battles, requires such an intense emotional commitment to the state being fought for that people are willing to die for the mission. That extends not just to combatants but the citizenry and polity behind them. Few wars of the modern era meet the bar. Wars of national survival may do, so long as the (defending) political class dont screw it up, eg by internal corruption.

tl;dr is that a state should not start a war unless they are prepared --truly prepared-- to finish it. I guess that's why so many politicians shy away from the word "war" to something else.

America has won every war it's fought since at least Vietnam.

Your convoluted extended definition of winning would mean that Germany never defeated Poland or France. Or the British never defeated the Irish.

It's really a testament to how blithely lethal the US military is that you look at the wholesale destruction of one of the largest, most effective non-superpower states in the world and can honestly say out loud "the US didn't win the Iraq war"