Coalition Of The Willing Take 2

Keir Starmer has been uttering the words 'Coalition of the WIlling' in regards to peacekeeping forces in Ukraine but anyone of a certain age will recognise the previous time this phrase was mentioned, by George W Bush in 2003 to invade Iraq more than two decades ago.
As the invasion was deemed illegal and was built on a tissue of lies about Weapons of Mass Destruction, Bush and his sidekick Blair managed to drum up support from 30 nations to support the invasion and remove Saddam Hussein including the military powerhouses of Estonia, Moldova, Dominican Republic, Honduras, Fiji Islands and El Salvador and led to eight years of chaos and bloodshed before fleeing and leaving Iraq to the terrorists who filed into the country.
Why Starmer and Macron, who are the brains behind the plan for Ukraine, decided on such a phrase with such awful connotations is what they went with is a bit of a strange choice but after the summit of leaders, Starmer said a number of other countries had agreed to join this coalition although he did not name them so who is in?
Led by the nuclear powers of UK and France, the initiative could see troops from a number of European and NATO countries deployed to Ukraine as peacekeepers in order to deter a nuclear armed Russia from breaking any ceasefire and Estonia, Lithuania and Latvia are also likely to be involved, especially as they border Russia and have obvious concerns for their own security.
The Finnish Foreign Secretary have said they will be part of the coalition as has Turkey, Spain, Australia and Canada but Poland, Italy and Germany have ruled themselves out and it is unlikely America will contribute with the ongoing weird Trump and Putin bromance.
In practise it all sounds great, send troops to stand as a buffer between Ukraine and Russia but in practise you have Russian troops pointing weapons at our troops and our troops pointing weapons at Russian troops which leads to two questions I have yet to hear answered.
The first is how long should we stay there? Ukraine is going to be bordering Russia for the rest of time so do we stay there until Putin leaves office and then hope the next guy is  not as warmongering and then leave them to it?
Secondly, and the most important, is if Russia does fire upon one of ours, will we fire back? Then we are into a war between heavilly armed nuclear powers and it's goodbye World in a mass of mushroom clouds.
I don't know the answer, I am torn between just ending the killing and not allowing Russia to get away with what they have done but by positioning ourselves to aim our  weapons threateningly at Russia on it's border is more than a tad provocative.
The last Coalition of the willing ended up as a complete catastrophe and this one has the potential to be even worse.