Oh I know. My point was that you can take civilians and turn them into an effective force in a short time.
Depends on your definition of "effective". Generally, the answer is "no, you can't".
Example: the First World War, in which American forces required over a year of intensive training with experienced teachers, along with some action in the actual trenches (albeit in quiet areas of the front). Even after that year-plus of training, however, American units were by and large still not as effective as other Entente ones. In particular, they took more casualties, were harder to maneuver, and infantry-artillery cooperation was poor until the final weeks of the war. American units achieved successes equivalent to those of the other Entente powers in the Hundred Days' fighting that ended the First World War, but it was harder and costlier in blood and treasure for them to do it. After eighteen months, the AEF was still only groping towards "effectiveness".
And eighteen months is only the time that those draftees and volunteers spent in the army, actually being trained and fighting. Prewar military socialization was also a Thing. Organizations like the Boy Scouts of America deliberately inculcated values and skills that happened to be useful for warfare: woodcraft, marksmanship, discipline, small-unit leadership. Imagine how much more difficult it would have been to make "effective" soldiers out of Americans without such experiences.
That was back when war was still
relatively simple. Trench fighting in 1918 is entirely different than commando raids in 2183. In most respects, that's because of a dramatic increase in complexity. Other posters have highlighted how much training has changed in the US military over the last few decades, and that's true. A similar quantum shift in training occurred in the late nineteenth century to deal with the "tactical crisis of the day", the firepower revolution that swept away linear formations and created the "empty battlefield". And that's just over the last century and a half: imagine the sorts of shifts we'd see after another 150 years.