Perhaps the most pro-active thing we can do is pray. It is absolutely the one thing that cannot be hindered, legislated or banned.
It doesn’t pre-empt being vocal or demonstrative, but it may add some real power to anything else that you do. Prayer is power.
I suggest a pray-in, and it should be private or public or wherever one desires to pray. Just do it.
If John Lennon and Yoko Ono considered a bed-in a powerful image in the case for peace, then I suggest a sustained, silent vigil is just the thing for sneaking up on the world and offering it something it needs.
Nothing is a quick fix, but why do we resist something so simple? The big question is: why not pray for peace?