The downing of flight MH17 could become a turning point in the west's economic relations with Russia. Since the Ukraine crisis flared up last year, sanctions have mostly been targeted at individuals and companies associated with Russia's annexation of Crimea or those stirring up unrest in eastern Ukraine. The European Union extended these sanctions on Friday, adding 15 names and 18 organisations (mostly companies) to the list.
As it stands, the list includes Kremlin officials, separatists and state companies. But the game could change this week, when the EU is expected to unveil more sweeping "tier three" economic sanctions aimed at entire sections of the economy. This weekend, diplomats have been examining proposals to restrict Russian state-owned companies from accessing capital markets, impose an arms embargo, and issue an export ban on specialist energy technology and "dual use" equipment, such as computers and machinery, that can be put to both civilian and military uses.
The draft proposal notes pointedly that European leaders should decide whether the arms embargo should be retrospective, thus annulling France'seuros 1.2bn contract to deliver Mistral assault ships to Russia.
Tightening the economic screws will hurt Russia's economy, but the consequences will also be felt by western companies - and not just the usual suspects of energy and arms companies that have made high-profile deals with the Kremlin. Germany, for example, has 6,000 companies doing business in Russia, mostly small and medium-sized enterprises. But large conglomerates will be the bellwethers, showing how serious the consequences will be.
While Russia faced anger over its annexation of Crimea earlier this year, BP insisted it was business as usual in its dealings with Moscow. BP has a 20% stake in the Russian state energy giant Rosneft - an alliance that was called into question when Igor Sechin, Rosneft's chairman and a close ally of President Vladimir Putin, was put on western sanctions lists earlier this year.
An export ban on European energy technology would almost certainly halt BP's plans to drill for oil in the Arctic, and scupper Russia's hopes of a fracking revolution. However, gas technology is unlikely to feature in the EU sanctions plan, due to Europe's dependence on Russian gas.
Exxon Mobil is helping Rosneft drill for oil in Siberia, while Shell is working with state-controlled Gazprom on oil and gas projects in the Far East. So far these companies have brushed off the threat of any seizures by Moscow, but with Russian politicians discussing tit-for-tat asset freezes, it is a risk they cannot ignore.
An easy way for Russia to retaliate against western sanctions would be to block the sale of metals that are widely used by car and aerospace companies. Few companies would be harder hit than US aerospace giant Boeing, which gets over a third of its titanium from Russia, and being forced to find another supplier at short notice could send costs up or slow down production of its planes.
If the Russian economy collapses, Boeing also stands to lose out on a share of building the next generation of Russia's airline fleet - a market the company estimates to be worth pounds 80bn-plus over the next 20 years.
The Anglo-Dutch consumer goods multinational Unilever admitted last week that business in Russia had been difficult. "You can imagine why", was how its chief financial officer summed up the problem.
Unilever, which makes Dove soap, PG Tips and Liptons tea, and Knorr stock cubes, gets more than half its income from emerging markets, including Russia, and in recent years the fast-growing, tea-loving Russian market has been a star performer in Europe, as sales have slowed elsewhere on the continent.
In company documents, Unilever has described Russia as crucial to its long-term plan to double its earnings. The effect of sanctions would be indirect, with a slowdown in the Russian economy and a likely freeze on new ventures.
According to the International Monetary Fund, Russia is officially in recession. In June, Unilever chief executive Paul Polman admitted that revenue growth in Russia had dropped to high single digits from double digits, although the company continued to gain market share. Other consumer companies in a fragile position include Carlsberg, which sells around a third of its drinks in Russia, largely as a result of its ownership of Russia'sBaltika brewery.
A McDonald's cheeseburger could be exhibit A in a Russian court this autumn, after Russian consumer protection officials declared this week that its sale was illegal because of "inappropriate physical-chemical parameters".
The case, brought by a branch of the consumer protection agency Rospotrebnadzor, is a shot across the bows of the fast food chain, in a country where consumer protection often turns political. In recent years, Russia's food safety agency has banned Georgian wine and water, Polish meat and European vegetables, usually at moments of political tension.
In April, McDonald's, which opened its first branch in Moscow to huge queues in 1990, announced the "temporary closure" of all three of its branches in Crimea, an act that prompted Vladimir Zhirinovsky, a nationalist politician, to call for it to shut all its Russian restaurants. An anti-American backlash is a risk for McDonald's, which counts Russia among its top seven global markets. McDonald's has not returned to Crimea, clearing the way for local chain Rusburger and its Czar cheeseburgers.
The City of London is often seen as the main loser from any attempt to freeze Russia out of the financial system. But the bank most exposed to political turbulence in Russia is probably Austria'sRaiffeisen Bank, with France'sSociete Generale in second place.
Little known in the UK, Raiffeisen is one of the biggest foreign banks in Russia. Its yellow-and-black crossed horse-heads logo has been a familiar sight in Russian cities since it started retail banking in 1996, cracking a notoriously difficult market that rivals HSBC and Barclays abandoned.
Raiffeisen earned three-quarters of its 2013 pre-tax profits from Russia and has euros 13bn in outstanding loans to Russia on its books.
The combination of the falling value of the rouble, a rise in loan defaults and the drying up of Russian bond markets would take its toll on the bank.
But many European financial institutions would feel the consequences of shutting Russia out of the capital markets. European banks accounted for three-quarters of all lending to Russia - around $155bn at the end of March, according to the most recent figures available from the Bank for International Settlements.
Clockwise from top: Boeing, PG Tips by Unilever, BP, McDonald's, Austria's Raiffeisen. Main photograph by Stephen Brashear/Getty