There has been some thawing of relations between North Korea and South Korea.
North Korea has not had nuclear tests for a few months.
North Korea and South Korea are having some communication and are trying to restart in person summits.
North Korea is attending the Winter Olympics in South Korea.
At War on the Rocks, Lt. Gen. David W. Barno, USA (Ret.) and Dr. Nora Bensahel is a Distinguished Scholar in Residence, at the School of International Service at American University make the case about the high risk and high cost of another Korea war.
War of the Rocks indicates the military effort, costs and casualties would likely be higher than the Iraq wars.
A 66 page Congressional Research Report – The North Korean Nuclear Challenge: Military Options and Issues for Congress indicates that the US will likely need about 700,000 troops to defeat North Korea.
In Dec, 2017, Senator Lindsay Graham estimated the chance of War with North Korea at between 30-70%. 70% is if there is another nuclear test.
The impact of renewed hostilities on the South Korean, regional, and global economies, especially should hostilities escalate into a full-scale war, would likely be substantial. According to one rough estimate by a 2010 RAND study, the costs of a conventional war could amount to 60%-70% of South Korea’s annual GDP, which in 2016 was $1.4 trillion. The study estimated that if North Korea detonated a 10 kt nuclear weapon in Seoul, the financial costs would be more than 10% of South Korea’s GDP over the ensuing 10 years. These figures should be treated as a rough order of magnitude rather than a precise costing estimate. Given the DPRK’s impoverished state, ROK reconstruction costs might also be affected by the costs of rehabilitating the North Korean economy.
Of North Korea’s 24 million people, 4% to 5% serve on active duty, and another 25% to 30% are assigned to a reserve or paramilitary unit and would be subject to wartime mobilization. Conscripts are required to serve for 10 years. With approximately 70% of its ground forces and 50% of its air and naval forces deployed within 100 kilometers of the DMZ, the KPA poses a continuous threat to the ROK and U.S. forces stationed there.