The U.S. government made the decision to retire the Lockheed SR-71 Blackbird seems rash and political. The program was initially cancelled in the late-1980s due to political reasons, not because it was obsolete. Although it was subsequently reinstated, there was a great amount of uncertainty of future funds. Decisions should be made on merit, not politics.
Sometimes we Americans keep our things and use them too long. This was an example of that. Not only that, but this was a deadly weapon aircraft that probably made other countries feel threatened even more than they already do by our super-power status. So I think it should have been retired.
When after some years of usage, these planes cannot be always relied upon they have to be grounded and sold to private parties so these people can fix them and use them for other purposes than government. It is perfectly reasonable for the government to buy new planes after some years.
The US Government did make the right call in retiring the Lockheed SR-71 Blackbird. That was the right call because we don't need such powerful weapons flying around our world. Long-range reconnaissance and weaponry are superlative and only encourage violence and hatred between the US and other countries around the world