Defence, like all other government branches, must justify it's existence and budget.
We are two weeks away from a general election so it is little wonder that defence is a key voting decision for the 100's of thousands employed in the defence industry often in key constituencies.
That aside, the Army is no doubt feeling it's the poor sibling to the investments made in the navy and air force state-of-the-art equipment purchases and now feel the time is right to pitch for more resource.
All democratic countries do it: publicise a general threat and the risk to protecting sovereignty and economy in order to generate public and ministerial demand, then produce manifesto pledges to secure funds and votes.
Autocracies and dictatorships are no different - especially where large parts of their economy are dependent on defence equipment exports (Russia) and use propaganda to justify a false threat mantra and hence keep it's internal economic failure and population suppressed.
in the case of China, economic success (greatly helped by Western consumerism and Capitalist politics), has provided the financial resource to develop and consolidate global reach. That expansion can be viewed as a passively-aggressive neo-colonialism whilst deflecting not only internal critique (public control) and external pressure (historical reference and hypocrisy shaming) but also exerting economic leverage on all fronts.
In other words, all defence postures must be viewed in the context of political pursuasion, economic objectives and global influence. Defence strategic spending reflects and is aligned with those aims.