A broad question like this will necessarily need to be answered with the appropriate reference in terms of time frame, who and perspective. My take is as follows,

US Side:

• Trump: It will make him look tough and may benefit him at the ballot box.
• Military Industrial Complex: China is continued to be portrayed as an enemy for justification of continued high or increased military expenditure.
• Business: Some wins and some losses. But based on reports, there will be more losses due to a collapse in the global trading structure, more expenses to restructure manufacturing and supply chain, and loss in market share in China eg. Boeing.
• Farmers: Loss of a major agricultural product buyer with few options to replace it. Loss of growth opportunities.
• Manufacturing workers: There may be a small uplift in some sectors as they bring some work back to the US, the great majority will continue to either seek other low cost manufacturing countries or move out of the US to get around the tariff barrier for the global market eg. Harley-Davidson, Tesla.
• Consumers: CPI will go up as significant number of common household goods from clothing to furniture to electrical goods to building material get hit by the tariffs.
• Trade deficit: US has long lost its ability on large scale manufacturing of low to medium tech goods. It’s unrealistic to rebuild the supply chain at a cost competitive level. So without China, imports will need to come from other manufacturing countries, just less from China. As long the consumer demand is there, the total national deficit will still be there, just redistributed differently.

China side:

• Manufacturing: There’ll be losses due to the sudden tariff in the US market but given diversity of its global access in 2018, a significant portion of the losses will be made up by other markets as well as by domestic consumption. Short term pain will be encountered. However, its established and world leading manufacturing supply chain remains intact in the country to supply cost effective goods to the rest of the world.
• Technology: As the US has shown itself to be an undependable trading partner, willing to use critical technologies to hurt its competitor/s, the Chinese govt will double its investment and effort to increase self sufficiency, further emphasising the goals of Made In China 2025 strategy. There’ll be some pain in this sector in the short term but self sufficiency is attainable in the medium to longer term. Once reached, the value of US to China would depreciate further.
• Politics: The behaviours shown by the US has clearly demonstrated that the US is a bully to China as well as to its traditional allies and the world. Past images of leadership in freedom and liberty have been unequivocally erased. As such, US’s threat will enhance unity in the country, further justifying the already successful economic policies and now the political policies of the government. International credibility and stature will be enhanced once China can demonstrate it can withstand the assault of the US, justifying its ‘power’ status.
• OBOR: This grand project is continuing unabated and will ensure the economic survival and growth of China. As such, the government will increase its efforts despite US’s smear campaigns and competitive investments. The difference being, China has a clear win-win goal for the participants while the US can clearly be seen as a disruptor who has no longer term goals and benefits for those countries. And who knows what would happen with the next change of POTUS. China’s policy stability and constructive goals makes it a no-brainer.
• Military: China will continue its rapid development and deployment in this area to ensure security of its trade routes and to counter hostile US threats.

In terms of time frame, based on the above as well as general consensus, there’ll be pain for both sides in the short term. People and experts can argue on and on as to who has the bigger pain. What’s more important however is not a comparison of pains but individual country’s tolerance to pain. China wins here. Then there’s the much more interesting medium to longer term outlook. As for warfares, unless the offensive side can be stopped and defeated for the spoils, the defensive side will never have any gains. Every step forward by the offensive side is an additive loss to the defensive side (‘offensive military cost - value of land gain’ vs ‘defensive military cost + value land loss’). Switching back to China and the US, with all evidences pointing to the fact that unless the US annihilates China militarily, China’s rise is not stoppable but the rate of rise. In waging this economic war, US has committed itself to a high economic business cost along with expenditures internationally in attempts to counter China’s OBOR global investments, then there’s the continuing high expenditure on the military, none are revenue generating as how China is growing its invested money with every forward step. Adding all these up, the US is draining more and more of its finite economic resources, akin to later years of the USSR when it could no longer keep up with the US economically.

So my conclusion to this trade war is that certain characters and groups in the US will gain in the short term but over time, it’ll further weaken the US economically as well as its international standing. On the China side, certain aspects of the economy will suffer a loss in the short term but overall, the country will become more capable and resilient, greatly benefiting in the longer term.

As an add. I’m utterly surprised by Trump and his administration’s strategy. If they really want to ‘beat’ China and maintain US’s supremacy globally, they really should have come up with a strategy and doubled and triple its investments in fields that the US are strong at eg. Technology, agriculture, energy, service industry. Investments and policies that’ll generate rich returns and ensure US’s leadership. What they are doing in practice is effectively playing to China’s strength and wasting finite economic resources on arbitrary sensationalistic activities eg. Following China’s plan and to return to the moon. Spending billions to trillions on military equipments is but a paper tiger unless one is willing to use them. In time and faced with a major nuclear power, those expensive military gears will just age and get thrown out in 10–20 years ie. Wasted except for chest puffing exercises. China is no push over like Japan in the 80s, Trump and his neocon supporters have completely misread China’s depth and capabilities.