I didn't see a single thing wrong with Kerry's assessment. Paul is using a typical fallacy argument that conservatives and especially libertarians love displaying when discussing government: government isn't perfect, therefore government should stop doing x. In this case, foreign aid is far from perfect although as Kerry pointed out it has improved greatly. But instead of wondering how can we reform things, or stop the wrong doing, Paul's argument apparently is that we should cut off all aid unless it's going to Israel. That's not going to happen, so he gets to fold his arms and act like he "won" a point in an esoteric argument that has no impact on how things will be done. Which is why libertarians have never been successful in this country and never will be: they are incapable of working to fix things, and would rather spend their time fantasizing about completely toppling the system.
Which is why the tea party faux libertarianism is so dangerous to the republican party. Obama has had success making just enough changes to ensure long term, bigger changes in the future. Liberals complain about Obamacare but let's not kid ourselves: it's going to usher in a public option or single payer system in the near future. It's a short term bet on major long term success/change. If Obama had followed the tea party approach, he wouldn't have passed anything because he couldn't get 100% of what he wanted. You change the system one brick at a time, unless you have the power to make major changes. Nobody in government has that power now, due one party controlling the senate and the other controlling the house.
Think about all the shyt Obama has tried giving republicans, but they refused. An increase in the retirement age, straight up Medicare/Social Security cuts, etc. If the republican party was truly interested in ending entitlements they would have taken those concessions - which would be the greatest victory against "big government" in decades. Instead they dismissed them because they didn't want to compromise in other areas (raising taxes). In short, they'd rather demand entitlement cuts than actually cut entitlements. Just like Rand Paul's libertarianism, republicans don't want to change shyt.