If you are too well connected, you stop thinking. The clamour, the immediacy, the tendency to absorb other people's thoughts, interrupt the deep abstraction required to find your own way. This is one of the reasons why I have not yet bought a smartphone. But the technology is becoming ever harder to resist. Perhaps this year I will have to succumb. So I have asked a simple question: can I buy an ethical smartphone?

There are dozens of issues, such as starvation wages, bullying, abuse and 60-hour weeks in the sweatshops manufacturing them, the debt bondage into which some of the workers are pressed, the energy used, the hazardous waste produced. But I will concentrate on just one: are the components soaked in the blood of people from the eastern Democratic Republic of the Congo? For 17 years, rival armies and militias have been fighting over the region's minerals. Among them are metals critical to the manufacture of electronic gadgets, without which no smartphone would exist: tantalum, tungsten, tin and gold.

While these elements are by no means the only reason for conflict there, they help to fund it, supporting a fragmented war that – through direct killings, displacement, disease and malnutrition – has now killed several million people. Rival armies have forced local people to dig in extremely dangerous conditions, have extorted minerals and money from self-employed miners, have tortured, mutilated and murdered those who don't comply, and have spread terror and violence – including gang rape and child abduction – through the rest of the population. I do not want to participate.

None of the campaigning groups wants companies to stop buying minerals from eastern Congo. Global Witness and FairPhone, for example, point out that mining supports many families in a country where 82% are considered underemployed. But they also insist that the trade can be dissociated from violence: if, and only if, companies ensure they're not buying minerals which have passed through the hands of militias. Given the potential damage to their reputations, you might have expected these firms to take the issue seriously. With a few exceptions, you would be wrong.

I began with the retailers, and the results were disappointing. Vodafone, for example, claims to have developed a social and ecological rating system, enabling its customers "to make informed decisions about the mobile phone they choose to buy". Its website says this system "was launched in the Netherlands in 2011 and will be introduced to other European markets in 2012". But all you get when you click on the link is "page not found". In Dutch. As for its claim that an ethical score "is displayed next to the product, whether you are buying online or in store", I have been unable to find any such scores on its UK site.

O2 says: "We want to share information about the social and environmental impact of the products we sell, to help customers make the right decisions." Click on the link and what do you get? A list of its monthly tariffs. It does provide eco-ratings beside its phones, but the scores are unexplained, so we can't see which issues are taken into account.

Of the manufacturers, Nokia appears to have gone furthest, and its efforts are quite impressive. Since 2001 – long before most other companies began to take an interest – it has tried to remove illegally mined tantalum from its supply chain. It now instructs its suppliers to map the routes these metals take before they reach the company. The problem is far from solved: it tells me that "there has been no credible system in the electronics industry that allows a company to determine the source of their material". There are now six initiatives by governments, voluntary groups and companies to try to get the blood out of mobile phones, and Nokia is involved in all of them.

Apple's response was less detailed and less persuasive. To give you an idea of how complex the problem has become, it has discovered that its metals are supplied by 211 smelters, liberally distributed around the planet. Any of them could be using minerals seized by militias in Congo. But the fact that it has mapped its own supply chain is a good sign.

Two years ago Motorola launched a scheme – which looks credible – whose purpose is to buy conflict-free tantalum from eastern Congo. Projects of this kind, which start at the beginning of the long chain of suppliers, provide an income for local people, while guaranteeing that armed psychopaths have not profited from the sale of your phone. It's hard to see why all the manufacturers can't join it.

Other companies, hiding behind their trade associations, have done all they can to undermine these efforts. Two months ago a new provision of the US Dodd Frank Act, which obliges companies to discover whether the minerals they buy from Congo are funding armed groups, came into force. It should have happened before, but it was delayed for 16 months by corporate lobbyists. Thanks to their efforts, and after 17 years of ignoring the issue, companies will still be allowed to dodge their duty for another two years, by stating that they don't know where the minerals come from.

Even this was not enough for them. Three corporate lobby groups – the National Association of Manufacturers, the US Chamber of Commerce and the Business Roundtable – are now suing the US government to have the new law set aside. Global Witness has called on some of their members – including Caterpillar, Dell, Honeywell, Motorola, Siemens, Toyota, Whirlpool and Xerox – to publicly distance themselves from the lawsuit, without success.

It suspects that some firms are "using the anonymity provided by the industry associations to try to weaken the law", while making public statements about how ethical they are. I ran out of time to pursue this question, but perhaps we could crowdsource it. Let's contact the phone manufacturers to discover whether they belong to these lobby groups, and ask whether they will publicly denounce the lawsuit and suspend their membership until it is dropped. That would be a good test of where they really stand.

I haven't yet made a decision. There are all the other issues to investigate, including the remarkably short life of these phones (a Twitter poll I conducted suggests that most people replace them after between one and four years). Perhaps I will wait until FairPhone manufactures a handset. Or perhaps I won't bother. I might resign myself to less immediacy, less accessibility and a little more space in which to think.

Twitter: @georgemonbiot. A fully referenced version of this article can be found at Monbiot.com