How trustworthy is The Associated Press' Iran reportage?
Scarcely, at best. 
It's bad enough that tabloid mogul, Rupert Murdoch, sits on the AP board of directors as CEO and president of News Corporation, and that News Corp., via Murdoch-owned Fox News, employs the biggest cheer-leader for illegal regime-change in Iran — Alireza Jafarzadeh — who, despite his dubious position and track record, has been cited by AP, UPI, and other news media as an expert on Iranian military and nuclear affairs. 
It's bad enough that, of all available veteran journalists, AP hired former UPI mouthpiece, Pamela Hess. Her idea of good journalism is to retain the inside scoop by protecting the secrecy of government. Her stated calling as an embedded reporter was to make sure the U.S.-led genocide in Iraq was getting the sympathetic coverage she felt it deserved. According to AP's "STATEMENT OF NEWS VALUES AND PRINCIPLES," she is disqualified from being an AP staffer. 
It's bad enough that AP cites the analysis of David Albright, of all people, in technical nuclear matters. He's the pro-intervention "nuclear expert that never was."
It's bad enough that AP has done these things: they only eat away at the once-lionized news organization's already-diminishing credibility. What's worse yet is when they all come together and do tangible damage to the reader's perception. A relatively-mild yet still-dangerous example of this is a September 8 report on Russia and Iran's nuclear relationship. 
Under the byline of Vladimir Isachenkov and the editorial assistance of Ms. Hess, we learn that "[t]he Russian state-run company building Iran's first nuclear plant said Monday that preparations for the reactor's launch had entered their final stage."
The report further whistles, "Atomstroiexport chief Leonid Reznikov said that by year's end the company will take steps that will make the launch of the Bushehr plant 'irreversible.'"
Be worried! 
AP then dutifully cites the International Atomic Energy Agency as having nothing to say.
The suspense builds as we get the analysis of "[n]onproliferation expert David Albright," who "suggested that the steps referred to by Russia probably involved the loading of fuel into the reactor."
Are you scared yet? You're certainly neither comforted nor bothered by further elaboration on the "loading of fuel into the reactor." You are, however, promptly informed that "[t]he United States and other Western nations ... fear Iran is seeking to acquire nuclear weapons," and that "Iran agreed to return spent nuclear fuel to Russia to ensure it does not extract materials that could be used to make weapons."
Welcome to the world of editorial innuendo.
Of course no mention is made of the IAEA's explicit confirmations that there is no evidence even hinting that Iran is weaponizing its nuclear program. Also absent is the fact that Iran's 3–4% uranium enrichment rate is consistent with a civilian energy program, while a weapons operation would require at least an 85% level — practically unachievable for the Iranian program, especially given the uncommonly tight IAEA scrutiny under which it operates.
The conjuring of balance and the contriving of controversy are also par for the course when it comes to apologizing for self-destructive U.S. foreign policy. Extreme "he said/she said" dichotomies go hand-in-hand with the marginalization of third-party sources.
According to the AP editor, the most-authoritative, third-party IAEA "declined comment"; but one party did assert the allegedly-contentious legality of the Russo-Iranian partnership on Bushehr. "Russia says the plant's contract is in line with all international agreements aimed at preventing nuclear weapons proliferation," AP says bemoaningly.
That is not the statement of an independent analyst: it comes from a directly-involved party, and is weighed against neither IAEA safeguards nor any other legal yardstick. Instead, the Russian remark is subtly discounted by the dangling last sentence of the AP report from who else but U.S. State Department spokesman, Sean McCormack. "Quite frankly, the international system has at this point decided [Iran] can't be trusted," AP trumpets the State cog.
Meanwhile, the U.S.' neocon delegation at the United Nations has been so "trusted" within that "international system" these past few years: they've had to resort to lying to the world about an Iranian nuclear threat while coercing fellow U.N. nations to vote in favor of sanctions against Iran.
The irony-deficiency in AP's reportage here would be laughable save for the real danger it poses. As fair and balanced as these reports attempt to appear, they are fig leaves for U.S. and Israeli warmongers. They are carefully written so as to induce anti-Iranian and anti-Russian fear while making insane U.S. foreign policy appear beyond question.
Aside from qualifying such vague and broad-stroke claims as that last quote, if AP editors wanted to decidedly discount all independent analysts and authoritative third-party sources, they could: A) ban, once and for all, references to the IAEA, U.N. Charter, treaties, etc., from their reports on these topics (which, at the current rate, would amount to a formality), B) come out and state their loyalty to the neocon-Likudnik empire, or C) both.
But they'll do neither. McCormack's claim is disingenuous at the very least and a total inversion of reality at worst. And for any respectable news service — especially the world's "most trusted source for news and information" — both A and B are indefensible. The rule of law, the IAEA, the NPT, and the historical record contradict neocon-Likudnik foreign policy around which AP's editorial cookie-cutters are molded.
There is simply no moral or legal justification for the looting of every U.S. taxpayer toward the enrichment of empire via the shakedown of defenseless nations.
Therefore, lest U.S. and Israeli war criminals and their cronies in corporate media be incriminated, they'll just keep with the subtle editorializing, the innuendo, the he said/she said balancing act, and the omission of anti-empire truth — just enough to appear credible and objective to the vast majority of less-discerning observers.
 For starters, see CASMII's analyses. For more, see this writer's rants.
 Jafarzadeh and countless other Murdoch employees are proudly in favor of the continued use of hundreds of millions in U.S.-taxpayer dollars to subsidize U.S.-designated terrorist groups like the Mujahideen-e Khalq (MeK) toward regime-change in Tehran, contriving editorial fantasy to those ends as regular columnists and TV guests. Scan the editorial section of The Weekly Standard, Fox, or The New Republic for their Iran pieces — if you can bear to. For Jafarzadeh's media presence, see: spcwashington.com/content/section/5/26/.
 See: ap.org/newsvalues/index.html under "CONFLICTS OF INTEREST" — more specifically, "EXPRESSIONS OF OPINION" and "OUTSIDE APPEARANCES."
 Vladimir Isachenkov: "Russia prepares to launch Iran's nuclear plant." The Associated Press via MyWay News (apnews.myway.com//article/20080908/D932NGA80.html). Also located at WireDispatch (wiredispatch.com/news/?id=335784). AP editor's note: Associated Press Writers Pamela Hess and Anne Gearan in Washington contributed to this report.
 The quoting of a single word is not a bad thing; at times, it's the most appropriate. But, for AP and other lapdog news media, it's also a good way of using scare quotes without scare-quoting (paraphrase every word from a source except for the one with the most shock value). In other situations, this technique allows the editor to subtly discredit or marginalize a source with minimal editorial intervention perceived. For example, when only the word illegal, colony, or occupation is set off in quotes when a Palestinian or third-party source is describing the illegal Israeli occupation of Palestine, or when the word myth is double-quoted within the paraphrased remainder of the mistranslated Mahmoud Ahmadinejad remark on the Nazi Holocaust. (See: "Seas of Sleaze" by this writer.)