This new ceasefire could already be in place for a long time, WW3 was a bit
of a sensationalism based purely on the fact that they both have nuclear weapons....
which creates a stalemate.
This is not a cease fire leading to a permanent understanding like was possible in WWI and WWIII - every single person still needs 3+ liters of water per day in those countries, PLUS the food they grow. Which country will sign a treaty allowing their citizens to die?