If much of our military is obsolete, this is not a good reason for shrinkage , replacement and refurbishment rather.
You don't know how right you really are , a lot of USAF aircraft date from 60's 70's and 80's, the replacements for normal wear and tear amount to a slow attrition , steadyly reducing the number and strength.
I don't think you know that you have been getting things your way for many years now, the military is smaller and is scheduled for further reduction.
At the point that the military is no longer large enough to meet our treaty obligations , the world will have no policeman at all.
Remember the fighting in the Balkins during the Clinton years? Europe could and should have taken that project, but it isn't in their nature to keep peace.
I don't think we have a member old enough to recall the pre- WWII US and world situation, but most of us are likely to live to see its repeat.