In the end, Clinton is correct: Trump clearly does not possess the qualifications or the temperament to lead the United States. Unfortunately, Clinton’s critique leaves voters with only a “less bad” alternative to Trump rather than with a compelling vision of America’s role in the world.
Clinton’s speech was focused mainly on denouncing Trump for many of his more outlandish statements, and his tendency to be all over the map on foreign policy provided her with plenty of material to use. She scored her best hits when she criticized Trump’s desire to be unpredictable and his ignorance of the relevant issues, but she was trying a bit too hard when she painted Trump as someone likely to start a war over a personal slight. She said that it was easy to imagine that Trump might start a war after being insulted by a foreign government (it’s actually not that easy to believe), but it is even easier to imagine Clinton initiating a war for other very questionable reasons. Clinton was attempting to present herself as the responsible candidate, but it is impossible for an informed listener to forget that she has never seen a military intervention she didn’t want to support.
She dinged Trump for his stated interest in being “neutral” in negotiations between Israel and Palestine, and misrepresented what he meant in the process. This was an odd move for her to make when her own party is sharply divided over how one-sidedly “pro-Israel” U.S. policy should be. One might think that she would be trying to placate disaffected Sanders supporters at this point, and attacking Trump for being insufficiently “pro-Israel” is an odd way to go about it. In general, her recitation of conventional foreign policy platitudes seems unlikely to satisfy the Sanders supporters that are currently leery of her candidacy, and instead it just reminds them of the things they dislike about her. Clinton has already switched to general election mode and doesn’t seem worried about this.
There was more discussion of Clinton’s record in the speech than I thought there would be, but it was notable for what she included and what she left out. She made a point of talking up the nuclear deal and New START as part of her record, but these were the result of diplomatic initiatives that she grudgingly supported. Those agreements happened mostly because of the work of other diplomats, and it is unlikely that Clinton would have pursued the nuclear deal as Obama did if she had been in his position. Now that it has been negotiated and is starting to work, Clinton wants to take credit for something that was mostly Obama and Kerry’s doing in spite of her reluctance. Notably, she said nothing about her support for deeper involvement in Syria, and as I recall the Libyan war was never mentioned even in passing. Clinton had touted the intervention in Libya as “smart power at its best,” but remarkably she didn’t want to use this occasion to talk about it. Perhaps Clinton didn’t want to remind the audience that she was a leading supporter of a failed and unnecessary war, or perhaps her campaign didn’t think they needed to draw attention to her well-known reputation for hawkishness. Whatever the reason, Clinton presented herself as much more of a supporter of diplomatic engagement than she really is while obscuring her reliable support for military action.