Many answers point to the idea of substitution, and the amount of time it may potentially take for substitution to take place. Assuming the disruption of trade isn't a hostile act by China (lets imagine that China is under total quarantine because the Andromeda strain has broken out there), then there will be many knock on effects.
Low wage nations like India, Viet Nam, Indonesia and so on which have functioning industrial bases will see their wages rise dramatically since they will suddenly be on high demand. Billions of dollars of capital investment will also flow into these nations to start creating the factories which will be needed to replace the ones no longer available. This will create massive social and political turmoil as the older social and cultural orders are overturned by the new wealth.
The United States has been taking steps to increase the production of Rare Earth elements both in the continental US (reopening old mines, for example), and experimenting with mining the deep sea muds off the coast of Hawaii to recover these elements. These substitution efforts will increase. Africa may descend into chaos since the Americans and Europeans will not be inclined to let their industries be held hostage by raw material shortages, and substitution using clever design and local mining will do for African resources what American Fracking has done for global oil prices. Kicking resource prices down will demolish many third world economies if they don't have the work force and infrastructure for industrial production.
Older electronics will become repurposed and forced to stay in service for far longer than they were designed for. An entire service industry of refurbishing old machines will grow rapidly. As well, the software industry will focus on changing code in order to run more efficiently on older machines. "Bloatwear" will be out, and very elegant, stripped down code will be in. This will have interesting effects in the future as new production finally comes on stream, since the hardware will reflect the new ideas of coding. This will also cement the Western military advantage, since the American military and US civil society has the most and most advanced computers and IT infrastructure in both qualitative and quantitative terms. If you can keep using more and better computers than anyone else, then you will be farther ahead when new computer production comes on line.
As part of the substitution effort, the US may also jump start many experimental technologies like photonics computers, using DNA as a computing substrate or quantum computers which have no counterparts being manufactured in China (or anywhere else). The wait for new computers will then change into a wait for new low end computing devices like small microprocessors for cars or stoves, rather than higher end devices.
Since in the United States there is a "maker" culture of large size and sophistication, there will be a resurgence of thousands if not millions of new "brands" as small shops kickstart to making in demand items, while larger conglomerates which depend on imports will be left hanging or collapse. This might resemble the 1920's, when you could choose from almost 100 different automobile companies for your driving needs.
So for areas where there already is industrial infrastructure, the import substitution effort will take place quickly creating islands of relative prosperity. Developing nations which are on the way will rapidly develop to replace the mass production capabilities of China, but this may take a long time. Resource based economies might take a huge hit since there is no longer Chinese money propping them up, and Western nations will most likely be taking steps to use their own resources.
Local effects like wars, revolutions, political movements and so on will she to be looked at on a very detailed case by case basis.