This is your alignment. The possible alignments are either Non-Aligned, Eastern Bloc, or The West. If you are aligned with a bloc they might offer you assistance randomly. If you attack the opposite bloc ( not including Neutrals ) , then you can beg your bloc for aid and they might respond. If you align yourself with a bloc you must have a corresponding economic system or a mixed economy. If you stray in the opposing economic system your bloc will disown you when the turn changes. Policy can change your alignment as can random events. Your alignment will also will also decrease if your reputation is in the red (Pariah or lower).
You can buy alignment from the foreign policies tab, moving from Non-Aligned to either alignment requires one purchase (50k), but also lowers stability. Alignment naturally declines if your reputation is in the red or if you have the opposite economic systems.
The West Edit
If aligned with the West, you will have access to M14 rifles until you reach Almost Modern Equipment, M60 Patton tanks until you reach Advanced, M1 Abrams since you reached advanced, and F-8 Crusaders (which are slightly cheaper than the Eastern alternative of MiGs). All Western weaponry and aircraft are restricted to West-aligned nations. In addition, Western nations have a chance of receiving a random event in which you can boost the training level of your military, increase the size of your air force by the equivalent of one purchase, or receive cash.
Eastern Bloc Edit
If aligned with the Eastern Bloc, you will have access to AK-47 rifles until you reach Almost Modern, T-62 until you reach Advanced, and T-90 since you reached Advanced, and MiGs. Aligning with the Eastern Bloc is also a requirement to trigger the random event for One Party States.