*To my knowledge*, the Aegis is the only one that’s considered remotely effective against a real ballistic threat because most that have been successfully tested have very low success rates or have only succeeded in test tube environments as well as none having the 2000 mile detection range of the THAAD and AEGIS Systems. Even the Aegis was considered a practical failure until around 2014. Russia in particular has said even within the last few years that Aegis has created nuclear asymmetry and a risk to world peace.
https://www.bloomberg.com/news/articles/2016-10-11/russia-says-it-s-joining-china-to-counter-u-s-missile-defense
http://economictimes.indiatimes.com/news/defence/china-russia-slam-us-plan-to-deploy-thaad-missiles-in-south-korea/articleshow/54799652.cms
My reasoning with Israel ranking so far below the others and not a significant deterrent to the US is that 1) they’re too small and 2) all of their technology and manufacturing is sourced from the US. So without the US they’re relatively weak, particularly w/r/t manpower and production. I mean, they have a total population of 8 million. Also, without US support, their list of committed allies to fill the gap in production and support is very short.
The PAK FA to me (India’s 5th gen plane) remains to be proven. They haven’t even successfully developed an engine for it yet (they’re using an old stand in), the stealth capabilities are expected to be next to nothing given the design of the engine housing and lack of parallel geometry. While it may work out in some form, to date it’s only existed as a theoretical boogieman with a total of $8B in funding (vs $400B in development funding for F35). A lot of people look at the fact that Russia cut its total expected orders to less than 12 from more than 150 this year (while instead buying existing 4th gen planes) as a clear indicator of the expected strength of the program (vs 2,500 F35’s ordered and 180+ delivered for the US + 200 F22’s already produced). India’s order is expected to be less than 150 as well. This is a very indicative description of most of these giant boogiemen threats you hear about in popular mechanics. They are either just prototype rumors or boondogles that get axed after a production run of 10-20 while the US winds up with 2,000+ functional examples sitting on runways.
With Pakistan I’d just point to a very weak economic engine and outdated equipment as well as small population and a 25-34 year old literacy rate of 57% which does not bode well for combat expertise and discipline in a high tech environment.
Honestly, wikipedia isn’t a bad source for just reading a lot. I also read things like stuff from the TEAL Group, newspapers, sites like military.com and militaryaerospace.com, any aerospace news sites and then books and pieces on combat. I’m not really picky, I honestly do things like read top news hits from google news under keyword topics like (f35, aegis, littoral, china military, russia military) every day. I also grew up watching a ton of discovery channel and stuff like that. It’s super theoretical, but I thought the marine corps warfighting manual (MCDP 1) was interesting:
http://www.globalsecurity.org/military/library/policy/usmc/mcdp/