Actually with the nuclear war heads of USA an Russia would be enough for make all the water in Mars become liquid or a big part
Which is still a tiny fraction of that on Earth and it would all quickly get blown away in the solar wind without a strong magnetic field to hold an atmosphere which would be needed to hold the liquid water, if all the volatiles on Mars we’re vaporized it would still be colder and dryer than anywhere on Earth
If a largish rocky dwarf planet were crashed into Mars in just the right way to reset its core’s magnetic dynamo, then wait 500 million years for a new crust to form and hit it again with a good sized icy dwarf planet or maybe better a whole mess of huge comets and wait another 500 million years for all the ghastly chemistry to settle, maybe anaerobic microbes will clean it up an make oxygen;
But big devastating collisions are rare and only getting rarer around our neighborhood so Mars is going to continue to be dead or merely nearly dead but certainly more dead in the future