There are several ways for security partnerships, wishful thinking or not.
1) The way of the super power: USA, Both China and the USA are highly interdependent and faces similar threats, domestic terrorism, religion extremism. Both country control large land mass, have huge populations and a definitive culture which dominates their neighbors. Both the USA and China share common threats and will come up with similar solutions.
2) The way of the great powers: Mainly France, less so Germany and the UK. All of the traditional European great powers have a lot to offer to China in terms of technologies while China have a lot to offer in terms of man power, strategic counterbalance to the USA and to Russia. This is especially true to France which called upon Chinese laborers from the first world war and have a large active Chinese community. Also, France is known to be a rebel to the US lead cause in this and last century. Under US pressure, we have episodes like the Suez channel, the refusal/delay of American help to the french Indochina war. France have also proven that they are willing to step out of line in the American lead coalition, freedom fries - French refusal to condone the US Iraq and Afghanistan invasion?
3) The way of island nation strongholds: Cuba, Fiji, Taiwan, Indonesia. Just like how the UK and Japan is a natural fortress defended by vast bodies of water, history have shown that such nations are almost impossible to conquer by force and is a perfect spring board to project power (the UK was only successfully invaded by the Romans and the Normans, Taiwan was only successfully invaded by the Qing Chinese and the Japanese and Japan (Okinawa) was only successfully invaded by the Americans). Cuba and Indonesia is not particularly friendly to the western world and may be more open to Chinese benevolence, their lack of variety of resource make them dependent on imports which China may guarantee without the strings attached of the western world. While their strategic locations will allow China to project power and be able to influence trade passing through both the Pacific and the Atlantic meaning China can put some hurt on any western nation if the need arises.