Japan looks set to re-embrace the power of public spending with one of its biggest ever stimulus packages.

Slowing global growth, a higher sales tax and a string of natural disasters are giving policymakers in Tokyo plenty of reasons to lead a worldwide shift toward a double-barreled approach of supporting the economy through fiscal measures and ultraloose monetary policy.

That's good news for the Bank of Japan, which has appeared reluctant to ramp up its own massive stimulus program, as it strains at the limits of effectiveness.