The word '**measured**' would be appropriate, and particularly appropriate for the chosen example sentence.

> b. Of aspects of language: carefully weighed or calculated; regulated, moderated, restrained. Of a person: using language in a careful, restrained way.

[OED][1]


>Trump shocks world with **measured** response to Las Vegas massacre

[MashableUK][2]

[1]:http://www.oed.com/view/Entry/115508?rskey=GjNZ0v&result=2&isAdvanced=false#eid
[2]:http://mashable.com/2017/10/02/donald-trump-teleprompter-las-vegas/#4dYC5LVF2kq1