The phrase "action would be needed" is correct and usable in written English.
It can be used when indicating that some form of intervention or response is required in a given situation.
Example: "In light of the recent developments, it is clear that action would be needed to address the issues at hand."
Alternatives: "intervention would be necessary" or "steps must be taken".
He declared that firm action would be needed by Cambodia before normal relations could be resumed.
Analysts said tougher action would be needed to convince investors Russia can overcome its economic problems and stave off recession.
Asked specifically about the UK's financial health, Blanchard warned that action would be needed once the crisis was over.
Mr. Rumsfeld hinted then that more aggressive action would be needed than the routine patrols of no-flight zones in northern and southern Iraq.
One flood warning – meaning flooding was expected and immediate action would be needed – was issued for areas of Surrey and West Sussex around Gatwick airport.
Researchers identified maternal and reproductive healthcare as one of the 10 areas where action would be needed to reach this goal.
Report 6: The Revolving Drug Fund 2009 - The purpose of the work was to evaluate what actions would be needed to develop the RDF to a level where it would provide sustainable public support to the population, and enhance HGH services.
Instead of opening kits and trays, spiking extra intravenous drips, and moving patients, staff could have waited until there was some indication from the triage areas (either within the hospital or at the attack site) that such actions would be needed.
The problem is that those economists, working with the figures available at the time, grossly underestimated the collapse in spending and hiring which the country was facing, and the scale of government action that would be needed to offset it.
America's government is not even aware of the gap between its commitments and action, because almost nobody in authority understands the actions that would be needed to meet the commitments.No serious work whatever is under way within the government to link annual budgetary allocations with the international development goals the United States has endorsed.
