That one is actually easier to swallow than others if the implication is just that Obama is soft on threats. Every leader can be considered 'complicit' in that regard.
Unfortunately, the implication is that the Obama administration supports ISIS[0], and that Obama himself is actually sympathetic to their views[1].
Donald Trump, remember, doesn't even believe Obama is an American citizen, or legally qualified to be president to begin with. Believing Obama's a terrorist sympathizer isn't a stretch, if you already believe he's a crypto-Muslim plant conspiring to cover up his own illegitimacy.
I am not advocating for that devil, but the events from the recent years - active encouragement of replacement of secular government with Islamist ones. Deal with Iran that cements the Islamic revolution, support for Erdogan while he makes Turkey a theocracy, giant arms sales to Saudi Arabia, drone strikes that are effective Taliban and ISIS recruitment tools, arming Iraq army which only strategic move is to drop their gear for ISIS to use and flee. Either there is strong support for islamisation of the middle east or the recent administrations have no idea and clue what are they doing.
> Deal with Iran that cements the Islamic revolution,
Knowing what I know about the MiddleEast, I can assure you that Iran is a much better option than the Saudis. The Saudis basically owned the USG over the last couple of decades. Case in point: after 9/11, when all flights were grounded, a couple of special flights were allowed to fly zig-zag across the country, picking up Saudis so they could get out of the US before the FBI came knocking. And Saudis are the biggest exporters and funders of extremist Wahhabi version of Islam.
Iran, on the other hand, has a much more moderate version of Islam. There are still Jews in Iran who practice freely, for instance. I challenge you to find one Jew in Saudi Arabia who practices freely.
I enjoy criticism of our current administration as much as anyone, but I'm going to go with Hanlon's Razor and guess the latter: they have no clue what effective foreign policy looks like. I suspect that simply doing nothing at all (leaving all pre-existing policies and agreements in place) would have been more effective than what we have done. At least it would have appeared consistent and predictable.
That's not the implication, though. The implication is that Obama is a secret Muslim extremist and is actively collaborating with terrorists. "Soft on threats" is just the dog whistle.
Hmm, that's the interesting thing about implication, it's can be very ambiguous. If you leave something ambiguous knowing a small minority will misinterpret the real implication for something worse, and accept that as beneficial and make no move to clarify that point, are you implying that as well?