That makes no sense. He didn't act under Obama. NK has probably done more and more serious provocative acts in the short time Trump has been in office than the last three POTUS combined.
RJ:
Respectfully, I'm not sure that your assertion that "NK has probably done more and more serious provocative acts in the short time Trump has been in office than the last three POTUS combined" is necessarily accurate. By way of reference, here is a link to an April 2, 2013 article by the BBC:
http://www.bbc.com/news/world-asia-pacific-11811861 that provides a timeline of provocative acts by PRNK up to point in that time. In any event, do you think that it might be possible that the reason why PRNK has "probably done more and more serious provocative acts in the short time Trump has been in office" is because it now feels emboldened to do so as a result of its apparent "nuclear readiness"? (the title of this thread)
Taking action may result in serious negative consequences, both anticipated and unanticipated. Likewise, not taking action may also result in serious negative consequences, both anticipated and unanticipated, particularly so if you do nothing long enough that it becomes too late to do something. Being able to accurately identify the real problem, accurately assess what can and can't be done with the resources available and the circumstances at hand (which constantly change), accurately anticipate and gauge the potential costs and benefits from acting or not acting, and then make the best decisions possible at the time (all of which are based upon incomplete information) is supremely difficult.
Note that I am not taking shots at any President, past or present. We can all throw rocks and criticize with the benefit of hindsight, but unless and until we are faced with the awesome responsibility of being the President (and have access to the information and intelligence they have) it may very well be unfair to criticize Trump, Obama, Bush or Clinton (or earlier Presidents) for what was done or not done. Most of the easy problems were solved a long time ago. It is the "wicked" problems that remain.