If this was a guilty pleasure, go ahead and convict me. It's not, actually, but very valid sf instead. Yes, it would make more lit-oriented readers cringe, but it gets the job done. What job? Glad you asked. Sf should throw up mind-stretching what-if questions and then work hard to keep you entertained while it answers them. Ian Douglas' Solar Warden trilogy (though it may yet add more books) comes up with a nearly Douglas Adams level of questions about everything, mixing "Reptilian aliens, Nazis in space, time-traveling humans, kidnapped girlfriends, government psychics" and every conspiracy theory you the author could think of all in one "action-packed military sci-fi" adventure.
In Alien Agendas, our hero Mark Hunter once a Navy Seal special forces guy, is now in command of the Space Forces elite JSST One force, a mix of special forces types from all the different branches and assigned to Earth's big starship carrier, the Hinckelpopper, or something like that )I should go back and look it up). This all takes place in our present, though clearly in a slightly different timeline, because the historical dates don't quite match up. Otherwise it could be now and the Space Force's real mission and capabilities, including the Lunar base, are just under wraps.
Mark has a white whale of sorts, a girlfriend who was abducted a few books back and is currently in storage in an alien base under the Pacific. He knows this thanks to a gal who does remote viewing (we get fringe science along with the conspiracies) and he's been keen to get her and the hundreds. Thousands? of other abductees in storage out of hock, but the powers that be including MJ-12 (if you don't know, look it up) don't want to rock the boat.
Meanwhile, our Mars Base has been overrun by the Saurians, the time-traveling sentient dinosaurs that have entitlement issues about a bunch of mammals owning the planet, and his team is sent to clear out the lizards.
Action ensues.
One of the interesting things about Ian Douglas' mul-sf is that because it often takes place in the now or the near now, he does a good job of depicting the difficulty of adapting to OOTT (operations other than terra). The JSST-One is a new force and they're still getting their weightless footing and they're badly outgunned by advanced alien tech. Humanity has allies from across the timeline, but they're sort of cautious about how much help we should get because, you know...wiping out their future.
So, back to my opening comment. If Solar Warden is a guilty pleasure, I'll plead to the crime, if crime it be.