[Serious] Does Trump deserve some credit if Iran...

[Anomalocaris]

Actually, again, no.  The notion that Reagan build up contributed to Soviet break up is largely self-congratulatory wishthinking by conservatives in the west.   Soviet documents, archives and independent Russian historiography all show in fact the Soviet Union did not perceive the defense burden the Soviet state had to bear to have been appreciable increased by the need to respond to the Reagan build up or the strategic defence initiative.    

What did the Soviet Union in was a strong perception that the general trend where Soviet Union was catching up to the US in economic and technology through the 1950s and early 1960s had reversed through the 1970s, and by the mid 1970s the Soviet Union was falling further behind in total economic productivity and emergent technologies like computers.    The perception was this malaise demanded a fundamental reorganization of Soviet economy and society to overcomes.    Gorbachev wasn’t the first senior Soviet leader to perceive the need to implement this reorganization.  The KGB had been aware of it since early 1970s    In fact it was the KGB leadership that maneuvered to advance gorbachev’s career through the 1970s to put him at the top Soviet leadership to implement this reform, believing him to be both capable enough and young enough to see the reform through.  As it turns out Gorbachev handled the reform terribly and it was this that did in the Soviet state.

KGB head Yuri Andropov’s misjudgment of Gorbachev in the mid-1970 to early 1980 was to a far higher degree responsible for the break up of the Soviet Union in the end of 1980s than any thing Reagan did.

And, so, you don't think that Reagan's supposed "Star Wars" (which everyone today recognizes to have been nothing more than a paper tiger, and quite possibly, even today, impossible to implement on at least a practical level) program did not cause a burden on the Soviet Union's military & industrial complex, which perceived it to be a real threat to nuclear detente and the status quo?  Were not the Soviets themselves trying to keep-up with the West militarily, which caused additional strain on their economy which led to Perestroika?  Are you saying that the Reagan administration deserves no credit for the reforms that led to the Soviet Union's breakup?

soviet defence spending as part of GDP held largely constant throughout 1950s- late 1980s.    for the first part of that period, despite spending more as percentage of gdp on defence than the US, the soviet economy were gaining on the US.   during the second part the soviets were able to achieve strategic parity with the west on the same spending level as before.   so the spending that allowed the soviets to keep pace through the reagan era was clearly not bankrupting the soviet union.

specifically regarding SDI, soviet counters to SDI were asymmetrical and mostly both vastly cheaper to implement than SDI, and actually make the US much more vulnerable to an unanswerable surprise attack by basing nuclear weapon in orbital bombardment stations and thus reducing warning time of a strike from about 30 minutes to 3 minutes,  rather than less vulnerable compared to the status quo before SDI.  

to counter the possibility that SDI could delude the US into believing it could launch a preemptive strike that would decapitate the USSR leadership and then use SDI to diminish the damage from resultant disorganized retaliation to acceptable levels, the soviets instituted a system of fully automated full scale retaliation that took humans out of the loop.   it consist of a nationwide system that, upon detection of any unexpected nuclear explosion in soviet territory, lunch all soviet strategic nuclear weapons launch against the US automatically without human intervention. 

so had the cold war continued, SDI would spend the US into oblivion far sooner than it would have bankrupted the Soviet union, while causing the soviets to shift their nuclear deterrence to a new mode that gave a lot less warning, at the same time it caused the removal of checks and balances in the soviet retaliation launch procedures that made successful preemptive strike against ussr even more improbable, but at the cost of making  accidental all out nuclear launch more likely.

In a nut shell, SDI actually advantaged the soviets rather than the US, while greatly reduced the stability of nuclear stand off and increasing the probability of accidental nuclear armageddon.