LOL...Tet was a massive debacle and a crushing defeat for The North. As I pointed out earlier, the VC was destroyed during the Tet Offensive.
They were certainly diminished to the point of little more then menacing for the next few years. The TO of 1968 was a battle that the US won, but it was bloody and there were huge losses. After assuring Americans that the war would be won very soon, the TO was a big set back for Johnson, he withdrew his candidacy and his Vice President ran instead. The GOP threw out Nixon who campaigned on "peace with honor" (read: exit strategy) and he won the election, but he too might win a battle, but couldn't win the war. The NAV launched another massive attack in the middle of 72, while they were repelled again, again US losses were heavy and Americans were at the end of their rope, seeing that after years, and two administrations, this "conflict" couldn't be won, and they demanded, no, DEMANDED we get out. In the end, the objective of keeping south Vietnam an independent non communist state failed and the US came home. Many battles were won, but the war was lost, the objective failed and there was no soldier homecoming as with WW2. In fact it was rough on returning soldiers. So, short of accomplishing the objective, 58K soldiers died for nothing, and of course there was the treasure spent as well.
This is not unlike today's conflict, the Iraq war and the strength of the Islamic State, which is why they boast. Americans were told Al Qaeda would be a pushover, why a mere two months into it Bush was crowing that Al Qaeda was decimated. Yet there menacing attacks continued and increased in fact, at more then four hundred the year before the "surge". And those attacks, though lessened by the surge continued right on through Bush's final days in office and through our withdrawal. Al Qaeda and its various offshoots lives, are perhaps stronger then ever and menacing a lot more territory now then before US involvement in the region. Again, there was no victory, removing Saddam Hussein hasn't even been a victory, and a majority of Americans now feel that the Iraq war (which includes Saddam's removal) was a
mistake so, whether or not the current airstrikes are having a negative affect on the Islamic State will remain to be seen. In the meantime, whether they are, or are not, of course the Islamic State will be declaring that they are not.