A lot of people here bring up China and Russia as an example, and while they have good relations and presently aligned interests, I think many of us here are overstating the level of commitment in this relationship. "Allying" is a very strong word to describe China's partnerships with Russia and especially with Iran, a more fitting example would be the DPRK and it's cooperation with Russia, which is a lot closer to an Alliance than China's more "soft" strategic partnership.
There is no binding bilateral security agreement between Russia and China, no formal mutual defense pact etc.
Whereas the DPRK and Russia definitely do have this