What would Europe have looked like in 1960 if it had not been for Truman Doctrine and the Marshall Plan.

There is, of course, no way to know what
might have happened if things had been different.  You
could argue, however, that Western Europe would not have been so united against
communism by 1960 if it were not for the things you
mentioned.

If it were not for these things, Europe might
not have felt so sure that the US would defend them.  Turkey and Greece might have
become communist, giving the rest of the continent the idea that they might be next. 
The countries of Western Europe would have been poorer and less grateful to the US. 
This would have also made them more likely to become communist or to at least have some
sort of close relationship with the Soviet Union.

It is at
least arguable, then, that Western Europe would not have a relatively solid
anti-communist bloc in 1960 had it not been for the Truman Doctrine and the Marshall
Plan.