WASHINGTON -- The growing strategic partnership between China, Russia, Iran, and North Korea has become one of the defining security challenges facing the United States and its allies. In their recently published book Axis of Aggressors, Rear Admiral (Ret.) Mark Montgomery and his co-authors Bradley Bowman and Elaine Dezenski document more than 600 instances of cooperation among the four authoritarian states, arguing their coordination extends across military, technological, economic, and cyber domains.Montgomery, senior director of the Center on Cyber and Technology Innovation and senior fellow at the Foundation for Defense of Democracies, says the West continues to underestimate both the scale of this alignment and the risks it poses. RFE/RL spoke with him about Ukraine, Iran, simultaneous conflicts, and what the US military must do to prepare for them.RFE/RL: Is Washington underestimating China, Russia, Iran, and North Korea as an integrated authoritarian axis and how closely they coordinate?Mark Montgomery: To a great degree we underestimate their level of coordination, and therefore our responses to their collective actions are sometimes underwhelming. In the US, you can see this with Ukraine.Ukraine is clearly fighting Russia, Iran, North Korea, and China. Iran is providing Shahed drones -- not just thousands of drones, but also the technology to produce them domestically. The Russians are now producing their own Tehran-designed drones.North Korea provided 12,000 soldiers, and people focus on that. But they also supplied 5 to 6 million rounds of artillery and mortar ammunition. That's more than all of NATO has produced over the last few decades. Finally, China is backstopping Russia's war effort by providing microelectronics for ballistic, hypersonic, and cruise missiles that are striking Kyiv today.