Blowing up the Moon would create quite enough debris on orbits steep enough to fall on Earth and end all life. Leave our Moon alone.
Let's develop a good, strong drive and fetch a plenty of small asteroids into Earth orbit, somewhere between LEO and GEO because the satellites are very useful.
Crash them into each other gently, to break them apart into multiple meteorite-sized chunks, without spreading them by much. There, you have your ring.
Alternatively, decelerate the Moon gradually, until tidal forces are strong enough to overcome its gravity, tear it apart and let it form a ring.
Easy mode: Get the Chinese to launch four-five more of their anti-satellite rockets. (yes, even 2 should suffice; we're close enough for that!) This should increase the amount of space junk past the chain reaction threshold, as satellites hit by space junk explode into more space junk, very quickly turning the Earth LEO into a massive, shiny cloud of debris, and preventing all space travel for a next century or so.