Unfortunately for the United States there seems to be evidence pointing to the involvement of individuals working in U.S. agencies in this incident.

"One possible target of Malaysian terrorist plot (masterminded by Khalid Sheikh Mohammed) would be the Petronas Towers in Kuala Lumpur, the world's tallest buildings from 1998 until 2004. These Malaysian Islamist's connections with Badat and Al-Qaeda were uncovered just a few days after MH370 disappearance. The link was spotted by British media on 15 March 2014.[7] This idea were discussed later in a few newspaper but only until 19 March 2014."

https://en.m.wikipedia.org/wiki/Saajid_Badat

The convoluted terror plots pre and post 9/11 do not withstand much scrutiny and it will be interesting to see what develops in Khalid Sheikh Muhammed's case before he is killed.

https://news.yahoo.com/trial-date-set-9-11-plotters-guantanamo-report-185930076.html

TLDR The United States almost certainly had the capacity at the time of the crash to monitor all air traffic globally, and did so.

Most likely the United States has declined to provide information about the exact location of the impact in order to preserve its illusion of technological supremacy. Still, as long as the U.S. does not provide whatever 'secret' satellite data it has on mh370, and as long as the main body of the plane is not recovered, there will be suspicions about whether the U.S. might be hiding some more sinister secret regarding the plane. 

~

update 3 

Some interesting conspiracies involve a computer chip company. It is highly likely, perhaps the most plausible theory, that the crash involved a mix of political and corporate ambitions. This theory gains credibility by the fact that some parties online are trying to backdoor discredit it by pushing absurd versions that distract from more likely versions. 

"On March 8, 2014, Freescale announced that 20 of its employees were passengers aboard Malaysia Airlines Flight 370."

https://en.m.wikipedia.org/wiki/Freescale_Semiconductor

~

update 2

https://www.telegraph.co.uk/news/2019/07/16/investigators-discover-mysterious-200lb-load-mh370/ 

http://www.leparisien.fr/faits-divers/vol-mh370-revelations-sur-le-crash-mystere-10-07-2019-8114283.php 

http://www.leparisien.fr/faits-divers/disparition-du-mh370-le-deplacement-d-enqueteurs-francais-aux-etats-unis-fait-renaitre-l-espoir-des-proches-19-10-2018-7922919.php

https://mobile.twitter.com/GWattrelos

~

update

An interesting article on mh370 https://www.theatlantic.com/magazine/archive/2019/07/mh370-malaysia-airlines/590653/ .

At first glance it appears to have high credibility, but there are some problems. 

1) There is little doubt that the U.S. has the ability to track, and does track, all aircraft globally around the world. This can be deduced a number of ways. 

2) There is little doubt China is aware of the capability, but the U.S. still keeps it 'secret'. 

3) Consequently, in the aftermath of the disappearance, the U.S. had two choices, a) provide the coordinates of the crash, or b) engage in subterfuge to distract from any appearance of responsibility to provide that information. 

So, then it becomes obvious a person should look for confirmation that the article linked above contains subterfuge. 

There are a few things, from early in the article, that cast doubt on the credibility of that article. 

Among other things, many signatures of a government led disinformation project. 

1) The name of the supposed searcher leads people to follow several plausible trails https://www.reddit.com/r/roosterteeth/comments/97lfxs/blaine_gibson_on_flight_mh370_conspiracy_podcast/

2) The articles mentioning this character and his research are heavily concentrated specifically in certain media, in specific countries, often used to promote 'official' versions of questionable events. For example these specific media 'scooped' other media with inaccurate stories following the Khashoggi murder, stories that turned out to be untruthful. 

3) Similarly, the death threats and other intrigue are presented in such a way as to try to increase the credibility of the story, rather than simply provide background. 

4) There are indications the author of the article might have some connection to governmental agencies that are prone to interfere in media. Note "After the attacks of 9/11, Langewiesche was the only journalist given full unrestricted access to the World Trade Center site." https://en.m.wikipedia.org/wiki/William_Langewiesche

5) The author was also the only person from the press allowed at another crash site . "The press was excluded even from the staging area" ... "the investigators made an exception in my case." https://www.theatlantic.com/magazine/archive/1998/03/the-lessons-of-valujet-592/306534/ 110 people died on that flight, but the accident has no obvious political overtones. 

It may well all be a series of coincidences, but it would seem wise for the United States to devote some resources to producing the plane, rather than producing questionable news articles. 

~In Progress~

~

There have been a number of suspicious plane crashes in recent years. Two examples are

MH 370 March 8 2014 https://en.m.wikipedia.org/wiki/Malaysia_Airlines_Flight_370

Some background http://jeffwise.net/2018/12/22/the-mh370-miracle/

and

ET302 March 10 2019 https://en.m.wikipedia.org/wiki/Ethiopian_Airlines_Flight_302

These two are selected because

a) they appear to be discrete sabotage, as opposed to crashes like that involving TWA800 which were meant by those involved to be exposed, and

b) there is pressure on governments to minimize the fear of travel they might cause, so some information released publicly should be scrutinized, and

c) if they are part of a commercial competition i.e., both those crashes targeting Boeing, then it is likely this tactic will rapidly increase as more countries / corporations start competing for contracts. 

A massive settlement by the U.S. against Airbus coincides with the 737max debacle. The negotiations were supposedly ongoing for more than a decade, but the multi billion dollar settlement was only reached after the 737max crashes. Was an Airbus plot behind the crashes? If the 737max was a case of industrial sabotage it will be decades before it is known publicly. Such competition between major corporations does occur, but even governments do not investigate, because public awareness of something like that could cripple economies.

https://www.npr.org/2019/10/02/766404561/wto-says-u-s-can-hit-eu-with-7-5-billion-in-tariffs-over-airbus-subsidies

This is one symptom of the fiat economy and nationalist competition that will grow rapidly unless small, insulated, language based digital economies are encouraged.

~

1930s / 1940s 

"Before the Second World War, researchers in the United Kingdom, France, Germany, Italy, Japan, the Netherlands, the Soviet Union, and the United States, independently and in great secrecy, developed technologies that led to the modern version of radar. Australia, Canada, New Zealand, and South Africa followed prewar Great Britain's radar development, and Hungary generated its radar technology during the war." https://en.wikipedia.org/wiki/Radar 

1957

"In 1957 the Soviet Union launched the world's first artificial satellite, Sputnik 1. Since then, about 6,600 satellites from more than 40 countries have been launched. According to a 2013 estimate, 3,600 remained in orbit. Of those, about 1,000 were operational" https://en.wikipedia.org/wiki/Satellite 

1960s through 1990s

A vast amount of money is spent on classified military satellites by numerous countries. In the 1980s it was publicly known that satellites had the capability of seeing anywhere on the planet in near real time, but the resolution was classified, in other words it was not public if those satellites could distinguish an object of a specific size e.g. golf ball sized. A main focus of these satellites was airplane and missile activity in hostile countries i.e., monitoring aircraft and other artificial objects.

2001

September 11 attacks on various targets led to a blank check mentality that would have prioritized identifying all planes, but especially commercial planes, real time. That capability almost certainly already existed by the late 1970s, but the events of 9/11 would have provided far more funding. Enough satellites to monitor all commercial air space on the planet would probably have cost in the hundreds of millions, not the billions at that point. However the cold war mentality of limiting access to information ostensibly for strategic reasons but more accurately for other reasons, like 'the feeling of power' among military types, was still in play, as it is today. 

2007 / 2008

"In 2007 the Chinese military shot down an aging weather satellite, followed by the US Navy shooting down a defunct spy satellite in February 2008."

March 8 2014

MH370 disappears. "Of the 227 passengers, 152 were Chinese citizens." https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370 

China makes it clear in press conferences that they are aware of the capabilities of certain countries to track commercial aircraft real time. Their appeal was evidently presented in a sincere way, and provided an opportunity for the United States to start a global shift away from offensive military technology and towards a sustainable way of using military resources. The fact that the United States did not offer that help will probably have repercussions that most Americans will not notice for years. 

More problematically, The fact that the United States was not helpful in locating this wreckage might raise suspicions about the origin or cause of the plane loss, and could be perceived as an attempt to push China in a certain direction. 

...

In this event, exposure would most likely come through the diligent research of somebody like Pablo Dreyfus https://en.m.wikipedia.org/wiki/Pablo_Dreyfus . An interesting note “Bonin wordlessly banks the plane to the left. Suddenly, a strange aroma, like an electrical transformer, floods the cockpit, and the temperature suddenly increases." https://www.popularmechanics.com/flight/a3115/what-really-happened-aboard-air-france-447-6611877/ 

In fact the transcript was kept secret until it leaked, and the odor right before the crash was minimized. 

...

https://en.wikipedia.org/wiki/USA-193 

https://en.wikipedia.org/wiki/List_of_passive_satellites 

https://en.wikipedia.org/wiki/List_of_Earth_observation_satellites

https://en.wikipedia.org/wiki/Flight_MH370:_The_Mystery

https://en.wikipedia.org/wiki/Malaysia_Airlines_Flight_370_unofficial_disappearance_theories

Worth adding / considering the following /

a) The debris collected suggests either the plane did not fly in the proper direction, or the debris was not deposited by a crash.

b) If the plane was not flying in the proper direction, then it is likely several passengers would have noticed.

c) It is almost certain that at least several passengers had satellite phones.

From that it seems likely that the passengers were probably incapacitated in some way. The most likely that comes to mind would be a gas similar to what the Russians used in the event described at https://en.m.wikipedia.org/wiki/Moscow_theater_hostage_crisis

**************

~~~The bottom line~~~

From http://nymag.com/daily/intelligencer/2015/02/jeff-wise-mh370-theory.html 

“For a long time, I resisted even considering the possibility that someone might have tampered with the data. That would require an almost inconceivably sophisticated hijack operation, one so complicated and technically demanding that it would almost certainly need state-level backing. This was true conspiracy-theory material.”

“And yet, once I started looking for evidence, I found it. One of the commenters on my blog had learned that the compartment on 777s called the electronics-and-equipment bay, or E/E bay, can be accessed via a hatch in the front of the first-class cabin. If perpetrators got in there, a long shot, they would have access to equipment that could be used to change the BFO value of its satellite transmissions. They could even take over the flight controls.”

~

So did the Russians take the plane to cause tension between the Chinese and the U.S.?

Or did the U.S. or U.K. frame the Russians?

Or did the Chinese frame the U.S.?

Who knows.

Some of the borders the plane would have to fly along are problematic, and the debris that has appeared off Madagascar seems to contradict some of this, but... Should the site referred to by Mr Wise be examined for evidence? 

 ~~~ 

 Best Final Guess / Summary Theory

1) A fairly capable and connected, but compartmentalized group, probably with connections in two or three countries, snatched the aircraft and its passengers.

2) The passengers were probably killed immediately. 

3) The primary motive was a future terrorist attack that would cement anti U.S. ‘conspiracy theories’ regarding the aircraft and lead to other countries, e.g. those involved, having a better stance in a world where China has more power.  

4) The specific status of the plane, e.g. location etc, was probably determined using capabilities described above. 

5) Specific individuals within U.S. agencies probably isolated the individuals involved by first leaking information to Mr Wise, then presenting the relevant imagery to representatives of several countries. 

6) The supposed debris off Western Africa provides discretion i.e., political closure, but does not reduce the chance of a flurry of similar attacks in the future, as full publicity of all the details would. 

7) The basic flaw of the individuals involved was their nationalism or provincialism, as long as the details are obscure the potential lessons are lost to the public.  

~What next?~

Because soft tissue remains would give a clear picture of what happened to the passengers, https://www.npr.org/sections/thetwo-way/2017/12/12/570189142/human-feet-still-washing-up-in-pacific-northwest-but-dont-panic and because the plane will have to be discovered at some point, most likely it has been deposited in such a way that much of the outside of the airplane has been ripped away. 

If the plane is to be used in some other event then the debris found would have to be replaced on the original plane, which would probably leave a clear trail for researchers. In that event the most likely target would be some Chinese interest, but that seems unlikely. 

If trauma to the passengers cannot be removed from the plane e.g. if they were shot while asleep as in the Moscow theater “rescue”, and bullet damage is evident to the plane, then the hijackers are in a truly difficult position. The various governments aware of what happened might help create an alternative scenario or help delay finding the plane, but in that case there would be a wide group of people with limited visibility who could be obliged to arrange cover for similar acts in the future. 

 https://en.m.wikipedia.org/wiki/Malaysia_Airlines_Flight_17

https://en.m.wikipedia.org/wiki/Vito_Miceli

https://en.m.wikipedia.org/wiki/Years_of_Lead_(Italy)

https://en.m.wikipedia.org/wiki/Operation_Gladio

https://en.m.wikipedia.org/wiki/Ren%C3%A9_Cogny

https://en.m.wikipedia.org/wiki/Itavia_Flight_870

https://en.m.wikipedia.org/wiki/Siberia_Airlines_Flight_1812

https://en.m.wikipedia.org/wiki/2016_Russian_Defence_Ministry_Tupolev_Tu-154_crash

https://www.nytimes.com/2001/10/10/world/russians-say-evidence-indicates-ukrainians-shot-down-jet.html

 Alternative theory / http://www.dailymail.co.uk/news/article-2592436/He-wasnt-father-I-knew-He-lost-disturbed-Daughter-MH370-pilot-raises-alarming-new-questions-state-mind-weeks-planes-disappearance.html