Leading up to the 1968 Tet Offensive, the Pentagon tried to convince the American public that it was winning the war.
General Bruce Palmer, Jr., one of Westmoreland's three Field Force commanders, claimed that "the Viet Cong has been defeated" and that "He can't get food and he can't recruit. He has been forced to change his strategy from trying to control the people on the coast to trying to survive in the mountains."
Just two months before Tet, Westmoreland said the North Vietnamese were "unable to mount a major offensive...I am absolutely certain that whereas in 1965 the enemy was winning, today he is certainly losing...We have reached an important point when the end begins to come into view." During an interview with Time magazine, Westmoreland mocked the North Vietnamese: "I hope they try something, because we are looking for a fight."

The concept of a credibility gap didn't start in 1968, but it became a household term after Tet.
While we have not reached this generation's Tet Moment - the moment when the public finally realizes that our government has been lying to us and that we aren't winning this so-called global war on terror - that moment isn't too far in our future. You can measure our distance to the Tet Moment by the amount of shit the government and news media is shoveling.

For example, the Pentagon recently released a map of Iraq showing how much territory ISIS has been losing. It left out a critical piece of information.

The Pentagon’s map assessing the so-called Islamic State’s strength has only two categories: territory held by ISIS currently, and territory lost by ISIS since coalition airstrikes began in August 2014. The category that would illustrate American setbacks—where ISIS has actually gained territory since the coalition effort began—is not included.

By looking only at successes and not at setbacks, Brig. Gen. Thomas Weidley was able to make this determination: “We believe across Iraq and Syria that Daesh is losing and remains on the defensive,”
Or to put it another way, Pentagon Claims ISIS Is on the ‘Defensive,’ Never Mind That City It Just Sacked.

Daesh lost an important battle in Tikrit where it was badly outnumbered, but it has been anything but defensive. They've been engaged in widespread counter-offensives across Syria and Iraq all month long, but the center of this offensive is the capital city of Anbar province, Ramadi.

Isis forces stormed the government-held enclave in central Ramadi, the capital of Anbar province, early on 15 May. The government still holds an operations centre on the edge of the city and important bases nearby, but its failure to defend Ramadi is a sign that Isis has become a permanent feature of the political and military landscape of Iraq.

That is the key sentence.
The Tet Moment we reached in 1968 wasn't the moment that we realized we were going to lose. It was the moment we realized that we couldn't win.

The fall of Ramadi, one of the few remaining government strongholds in Anbar province covering a third of Iraq, shows that hopes of the Iraqi army and Shia militia forces reversing Isis’s gains of last year were premature and may never be realised. The biggest success of the government was the recapture of Tikrit, Saddam Hussein’s home town, but Isis committed only about 500 fighters to defend the city. It has remained a ghost town ever since, ruled by Shia militias and local police, but with none of its original Sunni inhabitants daring to return.

Those two sentences tell the story. The Iraqi forces, made up almost entirely of Shia militias, defeated Daesh in a large Sunni town. It was a huge military victory for Baghdad and Tehran.
However, the core problem of Iraq isn't a military one. The core problem of Iraq is a political one, and there has been no real effort to fix that political problem. There has been no reconciliation between Shia and Sunni forces at all.
Baghdad simply cannot declare anything but successful ethnic cleansing if the civilians are fleeing before their forces and not coming back. A pilot project to train and arm Sunni militias to fight Daesh is also failing badly.

The Shia militias most effective against Daesh are directly supported by Iran, and only now are people waking up to the fact that Tehran might not be all that interested in winning this war.

Iran does want to keep control of Baghdad and Damascus, but Iran also has something to gain in allowing ISIS to continue operating in some other areas because as long as ISIS remains a threat, Iran can claim that their allies in Syria and Iraq are the only thing preventing a jihadist takeover, thereby preserving Iran’s influence in those two cities.

Even if Tehran decides that it is in their interest to push Daesh out of Iraq, that doesn't win us the war. Half of Daesh is in Syria, where none of the three major factions appear capable of defeating the others.

If Rikab is correct, then Syria isn't really reaching a turning point. Instead, the conditions that have made the conflict so deadly even during its stalemate period - namely the rise of violent jihadist groups, the marginalization of a secular and nationalist opposition, and the persistent survival of Assad in the country's coastal and urban areas - will only become more entrenched, without moving the war any closer to a resolution.

In Iraq, with the exception of Tikrit, Baghdad has really only been effective in mixed areas not dominated by Sunnis. The story is similar in Syria, where Damascus has managed to hold into its core Shia areas, while being defeated and thrown back in areas of mixed ethnicities.

The dramatic recent successes of Jabhat al-Nusra, al-Qaeda's affiliate in Syria, and President Assad complete inability to respond militarily to those advances means that the Syrian government and their Hezbollah allies will not be able to defeat the jihadists. Until the jihadists prove they are able to take one of Assad's core cities, they are unlikely to win the war as well.
If you were thinking that the Kurds were going to break this stalemate, think again. When was the last time you heard about a major offensive by the Kurds? You haven't because the Kurds are only interested in Kurdistan. A quick reading of Kurdish history will tell as much.

Let's not forget Afghanistan, America's longest war.
Recently Forbes published this fluff piece worthy of the infamous Five O'Clock Follies giving five reasons why Afghanistan should be considered a rousing success.
The article is rediculous for lots of reasons, but let me take one example to give you an idea. To quote the article, “55% believe their country is headed in the right direction — a better reading than similar surveys register in the U.S.”
That sounds good until you consider that 65% of Afghanis fear for their lives and 3/4 of Afghanis were afraid of traveling across their own country. In fact the security situation in Afghanistan is so dangerous that "the Pentagon has banned members of Congress and their aides from traveling there this summer".
In fact, what we've done in Afghanistan is almost certain to unravel.

"The evidence strongly suggests that Afghanistan lacks the capacity -- financial, technical, managerial or otherwise -- to maintain, support and execute much of what has been built or established during more than 13 years of international assistance," said John Sopko, the special inspector general for Afghanistan reconstruction, in an address at the Center for Strategic and International Studies on Wednesday.

To give you an idea of just how badly we've failed in Afghanistan, consider this quote.

Life has become a struggle — so much so that some residents pine for the days of Taliban rule.
“During the Taliban, we had city power and security. That was the best time,” said Sultan Mohammad

We've approached this Global Forever War with the attitude of a man with a hammer, seeing every problem as a nail. We've addressed political and economic problems with guns and bombs.
Trillions of dollars and thousands of lives later we haven't accomplished anything except killing a whole lot of people. The entire concept of defeating "terrorism" with military force is absurd in the extreme. Terrorism isn't a nation, a philosophy, or even a group. "Terrorism is a tactic often used by the powerless against the powerful."
If you really wanted to stop terrorism you need to address the reasons for the terrorism. But America simply shut down after 9/11. A reasoned and logical debate of the issue was considered a sign of weakness, in the same way a child abuser just wants to "make a man out of his son".
We aren't going to win this war.