No Principles, No Dignity, No Power, No Deterrence
People without principles and dignity do not understand that these are sources of tangible power that create deterrence. People who evade projecting those elements of power are doomed to be deterred by those with dignity and principles – however odious and deplorable – such as Iran, Russia, and China down to the level of Turkey. They treat the US with constant verbal contempt and actual provocations, in the knowledge that they can bait the US with impunity. 
The attacks of 9/14 on Saudi Arabia's oil plants demonstrate this American tragedy. The immediate, tactical targets were Saudi, but they could well have been American CENTCOM targets with a similar level of damage sustained.
Out of the best intentions of sparing America wars, America will inevitably face both "war and shame". President Trump asked Senator Lindsey Graham "How did going into Iraq work out?" One would have expected the man who restored the bust of Winston Churchill to the Oval Office to consider how did the appeasement policy of Chamberlain work out and what was the cost to the US in lives a few years later. But even the understanding that in a world where America is no longer the guarantor of world order, the American economy will also tank is beyond the qualifications of a great hotelier and real estate mogul.
The 9/14 attacks, correctly referred to by Secretary of State Michael Pompeo as "an act of war", is a harsh humiliating blow dealt to the U.S., signaling an American multilevel failure:
First, there was a failure of deterrence. The Iranians took a
calculated risk and were proven correct. They view themselves the
military regional equals of the US and via their proxies even beyond the
American military officials openly betray their fear of Iranian power and retaliatory capability on CENTCOM targets and they thus make Trump's boast that the US is the world's strongest military power, empty posturing In fact it is Iran that is actually deterring the U.S. from any retaliation. Iran relies on its proven ability to act in the local theater while its results have a global ripple effect.
Secondly, it was a failure of U.S. intelligence (military, NSA, CIA and others). Apparently, there was no early warning about an operation that must have had dozens of parties engaged in the decision process, the secret planning and the preparations. Since May 2019, MEMRI has issued several strategic warnings about the Iranian threats to carry out such attacks, based on open Iranian sources.
Thirdly, the successful Iranian attack represented an American technological failure, as not a single cruise missile or drone was intercepted. Iranian Foreign Minister Jawad Zarif ridiculed the U.S., tweeting "Perhaps [the US is] embarrassed that $100s of blns of its arms didn't intercept Yemeni fire".
Fourthly, and most disturbingly, it is a case of political failure - no one in the U.S. administration expected such a bold direct Iranian attack. True, Iran has resorted to proxies to afford it deniability, but now the Iranian leadership has realistically gauged American hesitancy and conflict aversion and believed that Iran could risk making a direct attack, discounting the possibility of strong American retaliation. Considering the global effect of this bold attack, so far, the calculated risk has proven to be a sound bet.
Why The Attacks?
The attacks of 9/14 have nothing to do with the war in Yemen; it is about the U.S. sanctions. Iran is painfully squeezed and tries to ease the sanctions by applying force – for now only against American allies and U.S. interests. Iran will continue to do so until the sanctions are significantly eased, as long as it assesses that the penalty for these attacks is nil or bearable. This is not rocket science and only requires a basic comprehension and not secret intelligence.
What Can Now Be Expected?
1. No deterrent American response against Iran should be expected.
Knowing that the U.S. administration will not stand by the Saudis
militarily, KSA spokesmen and leaders have refrained from explicitly
accusing Iran, and have emulated the UAE leaders, who refrained from
pointing a finger at Iran after the attacks on their tankers on June
2019, even when
Iranian complicity had been proven.
2. Further Iranian attacks, based on the same Iranian logic, will take place in the future as a result of continued U.S. sanctions, and not due to any reaction by KSA, the U.S. etc. to Iranian attacks.
No American can gain from Iran's humbling of America. Any future
president will have to address the Iranian threat and restore America's
power, deterrence, principles and dignity, albeit at a much higher
price. The powers of evil cannot be tamed by American self-abnegation.
This lesson should have been assimilated in the previous century. With
all the justified aversion to Saudi Arabia due to the murder of
Khashoggi, Saudi crimes pale in comparison to the mega murders committed
by the Ayatollah regime in their ongoing unbridled drive for an Islamic
dictatorship. The real threat is Iran's quest for regional domination
and nuclear weapons. Ideally, presidential contenders should prioritize
these long range
considerations; realistically this is not going to happen.
* Yigal Carmon is the President and founder of MEMRI
 The American loss of dignity was on display in spades when Trump thanked the Iranians for not downing a manned US plane that flew alongside the downed American UAV. No wonder that the Iranians were further convinced of their moral superiority and the justice of their Islamic Revolution ideology.