We are not going to get the block 4 'now'. We weren't even going to get it 'now' three years ago before delays. It was going to be a gradual addition of capabilities through the 2020's. That has been delayed, probably by 3-4 years. That sounds like a lot and the JPO, LM, P&W and other suppliers need to get their act together. I'm all for inflicting pain on these folks (JPO, LM and other suppliers) through harder negotiations and other processes at the Trump team's disposal but it is still the fastest way to field capability for this decade and most of the early to mid-next decade. That, and buying as many F-15 EX's, the AF can build and ramping up the B-21 Full Rate Production (from say seven a year to 10-12 a year) etc. Even if you go all in on NGAD, its still a decade long effort so realistically a mid to late 2030s capability (in quantity). If you can't wait that long and need capability inside the 10-15 years it is going to take to develop and put the NGAD PCA in full rate production (and have sizable inventory), you will need to explore faster options and compromises like derivatives, or trimming requirements around long lead RDT&E items like propulsion, mission systems etc. Those come with their own risk.