The Allies are hoping that Kim will fire first and then they will unleash surgical strikes to eliminate the leadership and key target acquisition and tracking capabilities. There is no appetite for a ground warfare as that is where NK's strength is - huge numbers of foot soldiers. There will be no invasion but enough damage for N Korea to occupying themselves rebuilding the country's infrastructure for the next 50 years.
They will then do their usual propaganda of telling people how they fought the Americans to a standstill.
Yes, this is the most plausible scenario.
The US will unleashed a surgical strike on Nkorean missile and military installation and will seek to finished the whole NKorean leadership. Already Nkorean has responded with fury when the US mentioned Osama type raid on Nkorea. This show they are very aware how the US will respond should a war breaks out in the Korean peninsula and I guess they are extremely well-prepared for this scenario and even the US cannot pinpoint where the actual missiles are kept ( unlike the Arabs who often trumpet everything to the world)
The most important thing is that a war in the two Koreas will spell the possible end of Nkorea but it will also spell the immediate death of South Korea. The US cannot possibly act bravo to kill off the Nkoreans but letting its ally South Korea destroyed completely. Imagine Seoul with its modern skycrapers and economy ended up flattened and millions of people killed. There would be chaos to the world as well. It will be suicidal for Skorea as well as the US besides the crazy Nkoreans . Moreover, I doubt the Russians and Chinese would stood and watched while the US is at their doorstep knowing very sure the issue here is also America's creeping strategy to crave its Asian pivot and thwart China and Russian power in the Far East. There were no super powers next door of the Arab countries that the US invaded .
Already the Russian foreign minister gave a veil warning to the US on its B-52 bombers which China and Russian see as targeting them than the Nkoreans.
I shared the same thoughts that the Nkoreans even if attacked by the US will start a propaganda that it is their "invincible" military who fought the mighty US army to a standstill. I don't think the US or the conscripted Skorean military would want to have a land invasion of Nkorea and air attack can only work to a limited solution. In this case, just having air strike would give the Nkorean counter attack that could hurt Skorea even more. The Nkoreans have thousands of fighter jets (Mig-19 and 21) who could overwhelmed the US air force even if they are out-dated and old besides the hundred of thousands of artllery rockets and short range missiles. Air strike could not possibly destroy all of them.
Thus, all powers in this issue are well aware that any military conflict will not be to anyone benefit, not even to the US. Only naive observer will quickly dismissed the end of Nkorea without understanding that Skorea will be the first dead as well. Cool heads need to prevail as war will mean Asia will be in tatters aftermath.