The only way to end wars is for nations not to participate in them. Despite its recent loss of respect under the Trump presidency, the US is still a major, international trend-setter. And the example we are setting is one of war, all the time. Usually, we avoid war with any group or nation which can fight back and engage only where we have the overwhelming advantage.
In regard to he Ukraine war
: We are cynically using the Ukrainians to fight a war we are not willing to engage in ourselves. We are using their willingness to fight for
the enrichment of our own Military-Industrial Complex. President Biden is happy to fight until the last Ukrainian is dead. (That doesn't mean I don't approve of most of his domestic policies).
The killing has to end and be replaced by serious negotiations with some compromise possible. Economic sanctions on Russia can still be continued, contingent on how the negotiations proceed. International pressure needs to be put on both Ukraine and Russia to stop the killing.
The key to ending war is non-participation.