Based on post-2000 scholarly research, how do Christians defend that it was Jesus himself who prophesied the first Jewish-Roman war?

How do Christians defend Jesus's prophecy? As a modern, post 2000 scholar, I would simply refer doubters to the writings of a respected historian, Dr. Lucius, and his erudite history of the Early Church: the Book of Acts. Notice his record of Stephen's trial in front of the august body of rabbinical judges and scholars:

This man (Stephen) ceases not to speak blasphemous words against this holy place, and the Law; for we have heard him say that this Jesus of Nazareth shall destroy this place... (Acts 6:13-14)

There is great legitimate presumption that Stephen was passing along Jesus's pronouncement of Destruction from the telling of the Olivet Discourse:

Verily I say unto you, There shall not be left here one stone upon another, that shall not be thrown down. (Matthew 24:2)

It is possible that the rabbis were also referring to Jesus "allegorical" statement about "resurrecting the Temple after three days." But here we have an a prophecy about an actual physical destruction.

The modern Higher Criticism school would have to not only discount Matthew, but also Acts of the Apostles, which would be a gargantuan task. Note that Acts ended with Paul in prison (first time?). This is dated before the Destruction of Jerusalem, before 67-70 A.D.

Stephen's premature demise was just a few years after the Ascension of Jesus, and he was spreading the prophecy of Jesus in his sermons (synagogue debates). This was a long time before the Destruction occurred.

(There is a Latin term for writing prophecies after the event: ex post eventium sp.? It's used quite a bit in dealing with Daniel, by Higher Critics.)

This answer will not use Innerancy. (I personally believe this to have originated in Princeton, New Jersey, circa latter 1800's.) Since no reliance on Innerancy is used, no reliance on dating is used ether. If an individual chooses to believe books are written later then commonly claimed, or contain after the fact insertions, so be it.

The destruction of Jerusalem was accurately foretold in Daniel chapter nine, even if Daniel was a fraud.

Dan 9:26 list an order of destruction of both city and Temple. The destruction is indefinite, until the end of war.

Vs. 27 clarifies the desolation, to be focused on the sacrifice and oblation. Under this wording, the city could be rebuilt any number of times, after said destruction. However, that portion of the city involving sacrifice and oblation must be under perpetual desolation.

Even a later dating of Daniel, places the book prior to the era of Jesus's lifespan. It would render an after the fact alteration to Matthew, a mute point.

The potential threat poised to undermine both Daniel and Matthew is not scholarship in nature. It is rather de facto offering of sacrifice and oblation, prior to the end of war. This assumption holds the passage of centuries is irrelevant due to the indefinite nature of stated desolation.

This answer states, the target is any physical sacrifice and oblation attempt, with physical destruction, in any century.

It is a reasonable request, that answers "do not use the inerrancy doctrine." Your second request is that "the answer does not merely use generalized arguments that target a liberal assertion that most purported fulfilled prophecies are not really prophecies because the record was always written after the fact." But there's a problem of inconsistency here. I refer to the old saying, "What's sauce for the goose is sauce for the gander."

If these post-2000 liberal scholars you refer to have a vested interest in debunking the Christian view that Jesus made that one particular prophecy pre-A.D. 70, that has to be taken into account. Of course, they would never publicly admit to that, should that be true, but claim objective scholasticism is their only concern. Just because those scholars do not have "the inerrancy doctrine" is no reason not to bear in mind the possibility that they are out to disprove this inerrancy doctrine, and what better way to do that than to claim that Jesus never made that particular prophecy - that it was added into the gospel account post-A.D. 70?

This means, then, that if these modern scholars wish to have a level playing-field for this matter, they will acknowledge that the charge of possible bias holds equally good for them as it does for Christians. In other words, nobody should pretend that such possible bias does not exist. That is why this quote from a Christian source (on this very question) holds good:

"Suggested dates for the writing of the Gospel of Matthew range from as early as A.D. 40 to as late as A.D. 140. This wide range of dates from scholars indicates the subjective nature of the dating process. Generally, one will find that the presuppositions of the scholars greatly influence their dating of the Gospels.

For example, in the past many liberal theologians have argued for a later dating of many of the New Testament books than is probably warranted or valid, in an attempt to discredit or cast doubts upon the content and authenticity of the Gospel accounts. On the other hand, there are many scholars who look to a much earlier dating of the New Testament books...

There are scholars who believe the Gospel of Matthew was written as early as ten to twelve years after the death of Christ... One of the evidences of this earlier dating of Matthew’s Gospel is that early church leaders such as Irenaeus, Origen, and Eusebius recorded that Matthew first wrote his Gospel for Jewish believers while he was still in Israel. In fact Eusebius (a bishop of Caesarea and known as the father of church history) reported that Matthew wrote his Gospel before he left Israel to preach in other lands, which Eusebius says happened about 12 years after the death of Christ. Some scholars believe that this would place the writing of Matthew as early as A.D. 40-45 and as late as A.D. 55.

...Had the Gospels been edited before being written down, as some liberal scholars contend, then it was a very poor job. The writers left far too many “hard sayings,” and culturally unacceptable and politically incorrect accounts that would need explaining."

https://www.gotquestions.org/when-Gospels-written.html

Now, this may be the very type of Christian response that you do not want in answers, but I would point out that claims for a pre-A.D. 70 date for the prophecy come from people living shortly after all the New Testament documents had been written, and they had direct access to the earliest copies of them. Iraneus lived circa A.D. 130-200; He was taught by Polycarp of Smyrna who was a disciple of the apostle John. So, there is a direct link right back to one of the apostles who wrote a large percentage of the New Testament.

Origen lived circa A.D. 185-254. Eusebius of Nicomedia was a bishop who spoke at the A.D. 325 Council of Nicaea.

Now we are being asked to consider what non-Christian scholars, post A.D. 2000, say in contradiction to those well-educated men living in an era from less than 100 years after the death of the last gospel author. They did not have mere scraps of gospel manuscript copies in their hands. They knew the chronological pedigree of all these fully-intact documents. Further, if the claim is correct that the gospel accounts were tampered with post A.D. 70, then why were many of Jesus' other "hard sayings" not removed or watered down?

There are some 1,700 years' gap between the earliest recorded supporters of Jesus' making that prophecy pre-A.D. 70. and modern scholars denying it. I would really like to know if this is just an uncomfortable fact that they have given a body-swerve to, in the hopes that nobody else will see its note-worthiness.

Further, Jesus made many other prophecies about world events that would commence from his resurrection from the dead, events that will build up until his spectacular return. It would be nice to think these modern scholars would give every one of them the same examination they've given to Jesus' one about the destruction of Jerusalem, to see if they require the same negativity they've given to that one. Somehow, given that they are unlikely to believe in his resurrection, and consequently not in his sudden re-appearing in the future, that's not going to happen. They must think what they believe, and write what they feel is true, but the case for Christians dissecting their 'discoveries' requires them to first deal openly with the problems raised here.