This is more logic than English or grammar.
If something (X) is terrorism, then it is a serious crime. So T(X) implies S(x) where T(x) means x is a terrorism, and S(x) means x is a serious crime.
If something (X) is terrorism, then you have to report it. So T(X) implies R(x) where R(x) means you have to report x.
So we have two statements of the form
Forall x T(x) implies S(x)
Forall x T(x) implies R(x)
but we cannot deduce from this that
Forall x S(x) implies R(x)
It is easy to construct examples to show that we cannot infer 'S implies R' from 'T implies S' and 'T implies R'. For example if T is divisibility by 8, R is divisibility by 4 and S is divisibility by 2.
If, on the other hand, we had
Terrorism is a serious crime
You must report all serious crimes
then we could deduce that
You must report terrorism.
In this case, from 'P implies Q' and 'Q implies R', we may deduce 'P implies R'.